Exponentiation, rules, examples. Degree and its properties

It's time to do a little math. Do you still remember how much it is if two are multiplied by two?

If anyone has forgotten, there will be four. It seems that everyone remembers and knows the multiplication table, however, I discovered a huge number of requests to Yandex like “multiplication table” or even “download multiplication table”(!). It is for this category of users, as well as for more advanced ones who are already interested in squares and powers, that I am posting all these tables. You can even download for your health! So:

Multiplication table

(integers from 1 to 20)

? 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
2 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40
3 3 6 9 12 15 18 21 24 27 30 33 36 39 42 45 48 51 54 57 60
4 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72 76 80
5 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
6 6 12 18 24 30 36 42 48 54 60 66 72 78 84 90 96 102 108 114 120
7 7 14 21 28 35 42 49 56 63 70 77 84 91 98 105 112 119 126 133 140
8 8 16 24 32 40 48 56 64 72 80 88 96 104 112 120 128 136 144 152 160
9 9 18 27 36 45 54 63 72 81 90 99 108 117 126 135 144 153 162 171 180
10 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200
11 11 22 33 44 55 66 77 88 99 110 121 132 143 154 165 176 187 198 209 220
12 12 24 36 48 60 72 84 96 108 120 132 144 156 168 180 192 204 216 228 240
13 13 26 39 52 65 78 91 104 117 130 143 156 169 182 195 208 221 234 247 260
14 14 28 42 56 70 84 98 112 126 140 154 168 182 196 210 224 238 252 266 280
15 15 30 45 60 75 90 105 120 135 150 165 180 195 210 225 240 255 270 285 300
16 16 32 48 64 80 96 112 128 144 160 176 192 208 224 240 256 272 288 304 320
17 17 34 51 68 85 102 119 136 153 170 187 204 221 238 255 272 289 306 323 340
18 18 36 54 72 90 108 126 144 162 180 198 216 234 252 270 288 306 324 342 360
19 19 38 57 76 95 114 133 152 171 190 209 228 247 266 285 304 323 342 361 380
20 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400

Table of squares

(integers from 1 to 100)

1 2 = 1
2 2 = 4
3 2 = 9
4 2 = 16
5 2 = 25
6 2 = 36
7 2 = 49
8 2 = 64
9 2 = 81
10 2 = 100
11 2 = 121
12 2 = 144
13 2 = 169
14 2 = 196
15 2 = 225
16 2 = 256
17 2 = 289
18 2 = 324
19 2 = 361
20 2 = 400
21 2 = 441
22 2 = 484
23 2 = 529
24 2 = 576
25 2 = 625
26 2 = 676
27 2 = 729
28 2 = 784
29 2 = 841
30 2 = 900
31 2 = 961
32 2 = 1024
33 2 = 1089
34 2 = 1156
35 2 = 1225
36 2 = 1296
37 2 = 1369
38 2 = 1444
39 2 = 1521
40 2 = 1600
41 2 = 1681
42 2 = 1764
43 2 = 1849
44 2 = 1936
45 2 = 2025
46 2 = 2116
47 2 = 2209
48 2 = 2304
49 2 = 2401
50 2 = 2500
51 2 = 2601
52 2 = 2704
53 2 = 2809
54 2 = 2916
55 2 = 3025
56 2 = 3136
57 2 = 3249
58 2 = 3364
59 2 = 3481
60 2 = 3600
61 2 = 3721
62 2 = 3844
63 2 = 3969
64 2 = 4096
65 2 = 4225
66 2 = 4356
67 2 = 4489
68 2 = 4624
69 2 = 4761
70 2 = 4900
71 2 = 5041
72 2 = 5184
73 2 = 5329
74 2 = 5476
75 2 = 5625
76 2 = 5776
77 2 = 5929
78 2 = 6084
79 2 = 6241
80 2 = 6400
81 2 = 6561
82 2 = 6724
83 2 = 6889
84 2 = 7056
85 2 = 7225
86 2 = 7396
87 2 = 7569
88 2 = 7744
89 2 = 7921
90 2 = 8100
91 2 = 8281
92 2 = 8464
93 2 = 8649
94 2 = 8836
95 2 = 9025
96 2 = 9216
97 2 = 9409
98 2 = 9604
99 2 = 9801
100 2 = 10000

Table of degrees

(integers from 1 to 10)

1 to the power:

2 to the power:

3 to the power:

4 to the power:

5 to the power:

6 to the power:

7 to the power:

7 10 = 282475249

8 to the power:

8 10 = 1073741824

9 to the power:

9 10 = 3486784401

10 to the power:

10 8 = 100000000

10 9 = 1000000000

Enter the number and degree, then press =.

^

Table of degrees

Example: 2 3 =8
Degree:
Number2 3 4 5 6 7 8 9 10
2 4 8 16 32 64 128 256 512 1 024
3 9 27 81 243 729 2 187 6 561 19 683 59 049
4 16 64 256 1 024 4 096 16 384 65 536 262 144 1 048 576
5 25 125 625 3 125 15 625 78 125 390 625 1 953 125 9 765 625
6 36 216 1 296 7 776 46 656 279 936 1 679 616 10 077 696 60 466 176
7 49 343 2 401 16 807 117 649 823 543 5 764 801 40 353 607 282 475 249
8 64 512 4 096 32 768 262 144 2 097 152 16 777 216 134 217 728 1 073 741 824
9 81 729 6 561 59 049 531 441 4 782 969 43 046 721 387 420 489 3 486 784 401
10 100 1 000 10 000 100 000 1 000 000 10 000 000 100 000 000 1 000 000 000 10 000 000 000
11 121 1 331 14 641 161 051 1 771 561 19 487 171 214 358 881 2 357 947 691 25 937 424 601
12 144 1 728 20 736 248 832 2 985 984 35 831 808 429 981 696 5 159 780 352 61 917 364 224
13 169 2 197 28 561 371 293 4 826 809 62 748 517 815 730 721 10 604 499 373 137 858 491 849
14 196 2 744 38 416 537 824 7 529 536 105 413 504 1 475 789 056 20 661 046 784 289 254 654 976
15 225 3 375 50 625 759 375 11 390 625 170 859 375 2 562 890 625 38 443 359 375 576 650 390 625
16 256 4 096 65 536 1 048 576 16 777 216 268 435 456 4 294 967 296 68 719 476 736 1 099 511 627 776
17 289 4 913 83 521 1 419 857 24 137 569 410 338 673 6 975 757 441 118 587 876 497 2 015 993 900 449
18 324 5 832 104 976 1 889 568 34 012 224 612 220 032 11 019 960 576 198 359 290 368 3 570 467 226 624
19 361 6 859 130 321 2 476 099 47 045 881 893 871 739 16 983 563 041 322 687 697 779 6 131 066 257 801
20 400 8 000 160 000 3 200 000 64 000 000 1 280 000 000 25 600 000 000 512 000 000 000 10 240 000 000 000
21 441 9 261 194 481 4 084 101 85 766 121 1 801 088 541 37 822 859 361 794 280 046 581 16 679 880 978 201
22 484 10 648 234 256 5 153 632 113 379 904 2 494 357 888 54 875 873 536 1 207 269 217 792 26 559 922 791 424
23 529 12 167 279 841 6 436 343 148 035 889 3 404 825 447 78 310 985 281 1 801 152 661 463 41 426 511 213 649
24 576 13 824 331 776 7 962 624 191 102 976 4 586 471 424 110 075 314 176 2 641 807 540 224 63 403 380 965 376
25 625 15 625 390 625 9 765 625 244 140 625 6 103 515 625 152 587 890 625 3 814 697 265 625 95 367 431 640 625

Properties of degree - 2 parts

A table of the main degrees in algebra in a compact form (picture, convenient for printing), on top of the number, on the side of the degree.


Continuing the conversation about the power of a number, it is logical to figure out how to find the value of the power. This process is called exponentiation. In this article we will study how exponentiation is performed, while we will touch on all possible exponents - natural, integer, rational and irrational. And according to tradition, we will consider in detail solutions to examples of raising numbers to various powers.

Page navigation.

What does "exponentiation" mean?

Let's start by explaining what is called exponentiation. Here is the relevant definition.

Definition.

Exponentiation- this is finding the value of the power of a number.

Thus, finding the value of the power of a number a with exponent r and raising the number a to the power r are the same thing. For example, if the task is “calculate the value of the power (0.5) 5,” then it can be reformulated as follows: “Raise the number 0.5 to the power 5.”

Now you can go directly to the rules by which exponentiation is performed.

Raising a number to a natural power

In practice, equality based on is usually applied in the form . That is, when raising a number a to a fractional power m/n, first the nth root of the number a is taken, after which the resulting result is raised to an integer power m.

Let's look at solutions to examples of raising to a fractional power.

Example.

Calculate the value of the degree.

Solution.

We will show two solutions.

First way. By definition of a degree with a fractional exponent. We calculate the value of the degree under the root sign, and then extract the cube root: .

Second way. By the definition of a degree with a fractional exponent and based on the properties of the roots, the following equalities are true: . Now we extract the root , finally, we raise it to an integer power .

Obviously, the obtained results of raising to a fractional power coincide.

Answer:

Note that a fractional exponent can be written as a decimal fraction or a mixed number, in these cases it should be replaced with the corresponding ordinary fraction, and then raised to a power.

Example.

Calculate (44.89) 2.5.

Solution.

Let's write the exponent in the form of an ordinary fraction (if necessary, see the article): . Now we perform the raising to a fractional power:

Answer:

(44,89) 2,5 =13 501,25107 .

It should also be said that raising numbers to rational powers is a rather labor-intensive process (especially when the numerator and denominator of the fractional exponent contain sufficiently large numbers), which is usually carried out using computer technology.

To conclude this point, let us dwell on raising the number zero to a fractional power. We gave the following meaning to the fractional power of zero of the form: when we have , and at zero to the m/n power is not defined. So, zero to a fractional positive power is zero, for example, . And zero in a fractional negative power does not make sense, for example, the expressions 0 -4.3 do not make sense.

Raising to an irrational power

Sometimes it becomes necessary to find out the value of the power of a number with an irrational exponent. In this case, for practical purposes it is usually sufficient to obtain the value of the degree accurate to a certain sign. Let us immediately note that in practice this value is calculated using electronic computers, since raising it to an irrational power manually requires a large number of cumbersome calculations. But we will still describe in general terms the essence of the actions.

To obtain an approximate value of the power of a number a with an irrational exponent, some decimal approximation of the exponent is taken and the value of the power is calculated. This value is an approximate value of the power of the number a with an irrational exponent. The more accurate the decimal approximation of a number is taken initially, the more accurate the value of the degree will be obtained in the end.

As an example, let's calculate the approximate value of the power of 2 1.174367... . Let's take the following decimal approximation of the irrational exponent: . Now we raise 2 to the rational power 1.17 (we described the essence of this process in the previous paragraph), we get 2 1.17 ≈2.250116. Thus, 2 1,174367... ≈2 1,17 ≈2,250116 . If we take a more accurate decimal approximation of the irrational exponent, for example, then we obtain a more accurate value of the original exponent: 2 1,174367... ≈2 1,1743 ≈2,256833 .

Bibliography.

  • Vilenkin N.Ya., Zhokhov V.I., Chesnokov A.S., Shvartsburd S.I. Mathematics textbook for 5th grade. educational institutions.
  • Makarychev Yu.N., Mindyuk N.G., Neshkov K.I., Suvorova S.B. Algebra: textbook for 7th grade. educational institutions.
  • Makarychev Yu.N., Mindyuk N.G., Neshkov K.I., Suvorova S.B. Algebra: textbook for 8th grade. educational institutions.
  • Makarychev Yu.N., Mindyuk N.G., Neshkov K.I., Suvorova S.B. Algebra: textbook for 9th grade. educational institutions.
  • Kolmogorov A.N., Abramov A.M., Dudnitsyn Yu.P. and others. Algebra and the beginnings of analysis: Textbook for grades 10 - 11 of general education institutions.
  • Gusev V.A., Mordkovich A.G. Mathematics (a manual for those entering technical schools).

Why are degrees needed?

Where will you need them?

Why should you take the time to study them?

To find out EVERYTHING ABOUT DEGREES, read this article.

And, of course, knowledge of degrees will bring you closer to successfully passing the Unified State Exam.

And to admission to the university of your dreams!

Let's go... (Let's go!)

FIRST LEVEL

Exponentiation is a mathematical operation just like addition, subtraction, multiplication or division.

Now I will explain everything in human language using very simple examples. Be careful. The examples are elementary, but explain important things.

Let's start with addition.

There is nothing to explain here. You already know everything: there are eight of us. Everyone has two bottles of cola. How much cola is there? That's right - 16 bottles.

Now multiplication.

The same example with cola can be written differently: . Mathematicians are cunning and lazy people. They first notice some patterns, and then figure out a way to “count” them faster. In our case, they noticed that each of the eight people had the same number of cola bottles and came up with a technique called multiplication. Agree, it is considered easier and faster than.


So, to count faster, easier and without errors, you just need to remember multiplication table. Of course, you can do everything slower, more difficult and with mistakes! But…

Here is the multiplication table. Repeat.

And another, more beautiful one:

What other clever counting tricks have lazy mathematicians come up with? Right - raising a number to a power.

Raising a number to a power

If you need to multiply a number by itself five times, then mathematicians say that you need to raise that number to the fifth power. For example, . Mathematicians remember that two to the fifth power is... And they solve such problems in their heads - faster, easier and without mistakes.

All you need to do is remember what is highlighted in color in the table of powers of numbers. Believe me, this will make your life a lot easier.

By the way, why is it called the second degree? square numbers, and the third - cube? What does it mean? Very good question. Now you will have both squares and cubes.

Real life example #1

Let's start with the square or the second power of the number.

Imagine a square pool measuring one meter by one meter. The pool is at your dacha. It's hot and I really want to swim. But... the pool has no bottom! You need to cover the bottom of the pool with tiles. How many tiles do you need? In order to determine this, you need to know the bottom area of ​​the pool.

You can simply calculate by pointing your finger that the bottom of the pool consists of meter by meter cubes. If you have tiles one meter by one meter, you will need pieces. It's easy... But where have you seen such tiles? The tile will most likely be cm by cm. And then you will be tortured by “counting with your finger.” Then you have to multiply. So, on one side of the bottom of the pool we will fit tiles (pieces) and on the other, too, tiles. Multiply by and you get tiles ().

Did you notice that to determine the area of ​​the pool bottom we multiplied the same number by itself? What does it mean? Since we are multiplying the same number, we can use the “exponentiation” technique. (Of course, when you have only two numbers, you still need to multiply them or raise them to a power. But if you have a lot of them, then raising them to a power is much easier and there are also fewer errors in calculations. For the Unified State Exam, this is very important).
So, thirty to the second power will be (). Or we can say that thirty squared will be. In other words, the second power of a number can always be represented as a square. And vice versa, if you see a square, it is ALWAYS the second power of some number. A square is an image of the second power of a number.

Real life example #2

Here's a task for you: count how many squares there are on the chessboard using the square of the number... On one side of the cells and on the other too. To calculate their number, you need to multiply eight by eight or... if you notice that a chessboard is a square with a side, then you can square eight. You will get cells. () So?

Real life example #3

Now the cube or the third power of a number. The same pool. But now you need to find out how much water will have to be poured into this pool. You need to calculate the volume. (Volumes and liquids, by the way, are measured in cubic meters. Unexpected, right?) Draw a pool: the bottom is a meter in size and a meter deep, and try to count how many cubes measuring a meter by a meter will fit into your pool.

Just point your finger and count! One, two, three, four...twenty-two, twenty-three...How many did you get? Not lost? Is it difficult to count with your finger? So that! Take an example from mathematicians. They are lazy, so they noticed that in order to calculate the volume of the pool, you need to multiply its length, width and height by each other. In our case, the volume of the pool will be equal to cubes... Easier, right?

Now imagine how lazy and cunning mathematicians are if they simplified this too. We reduced everything to one action. They noticed that the length, width and height are equal and that the same number is multiplied by itself... What does this mean? This means you can take advantage of the degree. So, what you once counted with your finger, they do in one action: three cubed is equal. It is written like this: .

All that remains is remember the table of degrees. Unless, of course, you are as lazy and cunning as mathematicians. If you like to work hard and make mistakes, you can continue to count with your finger.

Well, to finally convince you that degrees were invented by quitters and cunning people to solve their life problems, and not to create problems for you, here are a couple more examples from life.

Real life example #4

You have a million rubles. At the beginning of each year, for every million you make, you make another million. That is, every million you have doubles at the beginning of each year. How much money will you have in years? If you are sitting now and “counting with your finger,” then you are a very hardworking person and... stupid. But most likely you will give an answer in a couple of seconds, because you are smart! So, in the first year - two multiplied by two... in the second year - what happened, by two more, in the third year... Stop! You noticed that the number is multiplied by itself times. So two to the fifth power is a million! Now imagine that you have a competition and the one who can count the fastest will get these millions... It’s worth remembering the powers of numbers, don’t you think?

Real life example #5

You have a million. At the beginning of each year, for every million you make, you earn two more. Great isn't it? Every million is tripled. How much money will you have in a year? Let's count. The first year - multiply by, then the result by another... It’s already boring, because you already understood everything: three is multiplied by itself times. So to the fourth power it is equal to a million. You just have to remember that three to the fourth power is or.

Now you know that by raising a number to a power you will make your life a lot easier. Let's take a further look at what you can do with degrees and what you need to know about them.

Terms and concepts... so as not to get confused

So, first, let's define the concepts. What do you think, what is an exponent? It's very simple - it's the number that is "at the top" of the power of the number. Not scientific, but clear and easy to remember...

Well, at the same time, what such a degree basis? Even simpler - this is the number that is located below, at the base.

Here's a drawing for good measure.

Well, in general terms, in order to generalize and remember better... A degree with a base “ ” and an exponent “ ” is read as “to the degree” and is written as follows:

Power of a number with natural exponent

You probably already guessed: because the exponent is a natural number. Yes, but what is it natural number? Elementary! Natural numbers are those numbers that are used in counting when listing objects: one, two, three... When we count objects, we do not say: “minus five,” “minus six,” “minus seven.” We also do not say: “one third”, or “zero point five”. These are not natural numbers. What numbers do you think these are?

Numbers like “minus five”, “minus six”, “minus seven” refer to whole numbers. In general, integers include all natural numbers, numbers opposite to natural numbers (that is, taken with a minus sign), and number. Zero is easy to understand - it is when there is nothing. What do negative (“minus”) numbers mean? But they were invented primarily to indicate debts: if you have a balance on your phone in rubles, this means that you owe the operator rubles.

All fractions are rational numbers. How did they arise, do you think? Very simple. Several thousand years ago, our ancestors discovered that they lacked natural numbers to measure length, weight, area, etc. And they came up with rational numbers... Interesting, isn't it?

There are also irrational numbers. What are these numbers? In short, it's an infinite decimal fraction. For example, if you divide the circumference of a circle by its diameter, you get an irrational number.

Summary:

Let us define the concept of a degree whose exponent is a natural number (i.e., integer and positive).

  1. Any number to the first power is equal to itself:
  2. To square a number means to multiply it by itself:
  3. To cube a number means to multiply it by itself three times:

Definition. Raising a number to a natural power means multiplying the number by itself times:
.

Properties of degrees

Where did these properties come from? I will show you now.

Let's see: what is it And ?

A-priory:

How many multipliers are there in total?

It’s very simple: we added multipliers to the factors, and the result is multipliers.

But by definition, this is a power of a number with an exponent, that is: , which is what needed to be proven.

Example: Simplify the expression.

Solution:

Example: Simplify the expression.

Solution: It is important to note that in our rule Necessarily there must be the same reasons!
Therefore, we combine the powers with the base, but it remains a separate factor:

only for the product of powers!

Under no circumstances can you write that.

2. that's it th power of a number

Just as with the previous property, let us turn to the definition of degree:

It turns out that the expression is multiplied by itself times, that is, according to the definition, this is the th power of the number:

In essence, this can be called “taking the indicator out of brackets.” But you can never do this in total:

Let's remember the abbreviated multiplication formulas: how many times did we want to write?

But this is not true, after all.

Power with negative base

Up to this point, we have only discussed what the exponent should be.

But what should be the basis?

In powers of natural indicator the basis may be any number. Indeed, we can multiply any numbers by each other, be they positive, negative, or even.

Let's think about which signs ("" or "") will have powers of positive and negative numbers?

For example, is the number positive or negative? A? ? With the first one, everything is clear: no matter how many positive numbers we multiply by each other, the result will be positive.

But the negative ones are a little more interesting. We remember the simple rule from 6th grade: “minus for minus gives a plus.” That is, or. But if we multiply by, it works.

Determine for yourself what sign the following expressions will have:

1) 2) 3)
4) 5) 6)

Did you manage?

Here are the answers: In the first four examples, I hope everything is clear? We simply look at the base and exponent and apply the appropriate rule.

In example 5) everything is also not as scary as it seems: after all, it doesn’t matter what the base is equal to - the degree is even, which means the result will always be positive.

Well, except when the base is zero. The base is not equal, is it? Obviously not, since (because).

Example 6) is no longer so simple!

6 examples to practice

Analysis of the solution 6 examples

Whole we call the natural numbers, their opposites (that is, taken with the " " sign) and the number.

positive integer, and it is no different from natural, then everything looks exactly like in the previous section.

Now let's look at new cases. Let's start with an indicator equal to.

Any number to the zero power is equal to one:

As always, let us ask ourselves: why is this so?

Let's consider some degree with a base. Take, for example, and multiply by:

So, we multiplied the number by, and we got the same thing as it was - . What number should you multiply by so that nothing changes? That's right, on. Means.

We can do the same with an arbitrary number:

Let's repeat the rule:

Any number to the zero power is equal to one.

But there are exceptions to many rules. And here it is also there - this is a number (as a base).

On the one hand, it must be equal to any degree - no matter how much you multiply zero by itself, you will still get zero, this is clear. But on the other hand, like any number to the zero power, it must be equal. So how much of this is true? The mathematicians decided not to get involved and refused to raise zero to the zero power. That is, now we cannot not only divide by zero, but also raise it to the zero power.

Let's move on. In addition to natural numbers and numbers, integers also include negative numbers. To understand what a negative power is, let’s do as last time: multiply some normal number by the same number to a negative power:

From here it’s easy to express what you’re looking for:

Now let’s extend the resulting rule to an arbitrary degree:

So, let's formulate a rule:

A number with a negative power is the reciprocal of the same number with a positive power. But at the same time The base cannot be null:(because you can’t divide by).

Let's summarize:

Tasks for independent solution:

Well, as usual, examples for independent solutions:

Analysis of problems for independent solution:

I know, I know, the numbers are scary, but on the Unified State Exam you have to be prepared for anything! Solve these examples or analyze their solutions if you couldn’t solve them and you will learn to cope with them easily in the exam!

Let's continue to expand the range of numbers “suitable” as an exponent.

Now let's consider rational numbers. What numbers are called rational?

Answer: everything that can be represented as a fraction, where and are integers, and.

To understand what it is "fractional degree", consider the fraction:

Let's raise both sides of the equation to a power:

Now let's remember the rule about "degree to degree":

What number must be raised to a power to get?

This formulation is the definition of the root of the th degree.

Let me remind you: the root of the th power of a number () is a number that, when raised to a power, is equal to.

That is, the root of the th power is the inverse operation of raising to a power: .

It turns out that. Obviously, this special case can be expanded: .

Now we add the numerator: what is it? The answer is easy to obtain using the power-to-power rule:

But can the base be any number? After all, the root cannot be extracted from all numbers.

None!

Let us remember the rule: any number raised to an even power is a positive number. That is, it is impossible to extract even roots from negative numbers!

This means that such numbers cannot be raised to a fractional power with an even denominator, that is, the expression does not make sense.

What about the expression?

But here a problem arises.

The number can be represented in the form of other, reducible fractions, for example, or.

And it turns out that it exists, but does not exist, but these are just two different records of the same number.

Or another example: once, then you can write it down. But if we write down the indicator differently, we will again get into trouble: (that is, we got a completely different result!).

To avoid such paradoxes, we consider only positive base exponent with fractional exponent.

So if:

  • - natural number;
  • - integer;

Examples:

Rational exponents are very useful for transforming expressions with roots, for example:

5 examples to practice

Analysis of 5 examples for training

Well, now comes the hardest part. Now we'll figure it out degree with irrational exponent.

All the rules and properties of degrees here are exactly the same as for a degree with a rational exponent, with the exception

After all, by definition, irrational numbers are numbers that cannot be represented as a fraction, where and are integers (that is, irrational numbers are all real numbers except rational ones).

When studying degrees with natural, integer and rational exponents, each time we created a certain “image”, “analogy”, or description in more familiar terms.

For example, a degree with a natural exponent is a number multiplied by itself several times;

...number to the zeroth power- this is, as it were, a number multiplied by itself once, that is, they have not yet begun to multiply it, which means that the number itself has not even appeared yet - therefore the result is only a certain “blank number”, namely a number;

...negative integer degree- it’s as if some “reverse process” had occurred, that is, the number was not multiplied by itself, but divided.

By the way, in science a degree with a complex exponent is often used, that is, the exponent is not even a real number.

But at school we don’t think about such difficulties; you will have the opportunity to comprehend these new concepts at the institute.

WHERE WE ARE SURE YOU WILL GO! (if you learn to solve such examples :))

For example:

Decide for yourself:

Analysis of solutions:

1. Let's start with the usual rule for raising a power to a power:

ADVANCED LEVEL

Determination of degree

A degree is an expression of the form: , where:

  • degree base;
  • - exponent.

Degree with natural indicator (n = 1, 2, 3,...)

Raising a number to the natural power n means multiplying the number by itself times:

Degree with an integer exponent (0, ±1, ±2,...)

If the exponent is positive integer number:

Construction to the zero degree:

The expression is indefinite, because, on the one hand, to any degree is this, and on the other hand, any number to the th degree is this.

If the exponent is negative integer number:

(because you can’t divide by).

Once again about zeros: the expression is not defined in the case. If, then.

Examples:

Power with rational exponent

  • - natural number;
  • - integer;

Examples:

Properties of degrees

To make it easier to solve problems, let’s try to understand: where did these properties come from? Let's prove them.

Let's see: what is and?

A-priory:

So, on the right side of this expression we get the following product:

But by definition it is a power of a number with an exponent, that is:

Q.E.D.

Example : Simplify the expression.

Solution : .

Example : Simplify the expression.

Solution : It is important to note that in our rule Necessarily there must be the same reasons. Therefore, we combine the powers with the base, but it remains a separate factor:

Another important note: this rule - only for product of powers!

Under no circumstances can you write that.

Just as with the previous property, let us turn to the definition of degree:

Let's regroup this work like this:

It turns out that the expression is multiplied by itself times, that is, according to the definition, this is the th power of the number:

In essence, this can be called “taking the indicator out of brackets.” But you can never do this in total: !

Let's remember the abbreviated multiplication formulas: how many times did we want to write? But this is not true, after all.

Power with a negative base.

Up to this point we have only discussed what it should be like index degrees. But what should be the basis? In powers of natural indicator the basis may be any number .

Indeed, we can multiply any numbers by each other, be they positive, negative, or even. Let's think about which signs ("" or "") will have powers of positive and negative numbers?

For example, is the number positive or negative? A? ?

With the first one, everything is clear: no matter how many positive numbers we multiply by each other, the result will be positive.

But the negative ones are a little more interesting. We remember the simple rule from 6th grade: “minus for minus gives a plus.” That is, or. But if we multiply by (), we get - .

And so on ad infinitum: with each subsequent multiplication the sign will change. The following simple rules can be formulated:

  1. even degree, - number positive.
  2. Negative number raised to odd degree, - number negative.
  3. A positive number to any degree is a positive number.
  4. Zero to any power is equal to zero.

Determine for yourself what sign the following expressions will have:

1. 2. 3.
4. 5. 6.

Did you manage? Here are the answers:

1) ; 2) ; 3) ; 4) ; 5) ; 6) .

In the first four examples, I hope everything is clear? We simply look at the base and exponent and apply the appropriate rule.

In example 5) everything is also not as scary as it seems: after all, it doesn’t matter what the base is equal to - the degree is even, which means the result will always be positive. Well, except when the base is zero. The base is not equal, is it? Obviously not, since (because).

Example 6) is no longer so simple. Here you need to find out which is less: or? If we remember that, it becomes clear that, which means the base is less than zero. That is, we apply rule 2: the result will be negative.

And again we use the definition of degree:

Everything is as usual - we write down the definition of degrees and divide them by each other, divide them into pairs and get:

Before we look at the last rule, let's solve a few examples.

Calculate the expressions:

Solutions :

Let's go back to the example:

And again the formula:

So now the last rule:

How will we prove it? Of course, as usual: let’s expand on the concept of degree and simplify it:

Well, now let's open the brackets. How many letters are there in total? times by multipliers - what does this remind you of? This is nothing more than a definition of an operation multiplication: There were only multipliers there. That is, this, by definition, is a power of a number with an exponent:

Example:

Degree with irrational exponent

In addition to information about degrees for the average level, we will analyze the degree with an irrational exponent. All the rules and properties of degrees here are exactly the same as for a degree with a rational exponent, with the exception - after all, by definition, irrational numbers are numbers that cannot be represented as a fraction, where and are integers (that is, irrational numbers are all real numbers except rational numbers).

When studying degrees with natural, integer and rational exponents, each time we created a certain “image”, “analogy”, or description in more familiar terms. For example, a degree with a natural exponent is a number multiplied by itself several times; a number to the zero power is, as it were, a number multiplied by itself once, that is, they have not yet begun to multiply it, which means that the number itself has not even appeared yet - therefore the result is only a certain “blank number”, namely a number; a degree with an integer negative exponent - it’s as if some “reverse process” had occurred, that is, the number was not multiplied by itself, but divided.

It is extremely difficult to imagine a degree with an irrational exponent (just as it is difficult to imagine a 4-dimensional space). It is rather a purely mathematical object that mathematicians created to extend the concept of degree to the entire space of numbers.

By the way, in science a degree with a complex exponent is often used, that is, the exponent is not even a real number. But at school we don’t think about such difficulties; you will have the opportunity to comprehend these new concepts at the institute.

So what do we do if we see an irrational exponent? We are trying our best to get rid of it! :)

For example:

Decide for yourself:

1) 2) 3)

Answers:

SUMMARY OF THE SECTION AND BASIC FORMULAS

Degree called an expression of the form: , where:

Degree with an integer exponent

a degree whose exponent is a natural number (i.e., integer and positive).

Power with rational exponent

degree, the exponent of which is negative and fractional numbers.

Degree with irrational exponent

a degree whose exponent is an infinite decimal fraction or root.

Properties of degrees

Features of degrees.

  • Negative number raised to even degree, - number positive.
  • Negative number raised to odd degree, - number negative.
  • A positive number to any degree is a positive number.
  • Zero is equal to any power.
  • Any number to the zero power is equal.

NOW YOU HAVE THE WORD...

How do you like the article? Write below in the comments whether you liked it or not.

Tell us about your experience using degree properties.

Perhaps you have questions. Or suggestions.

Write in the comments.

And good luck on your exams!

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For successfully passing the Unified State Exam, for entering college on a budget and, MOST IMPORTANTLY, for life.

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GAIN YOUR HAND BY SOLVING PROBLEMS ON THIS TOPIC.

You won't be asked for theory during the exam.

You will need solve problems against time.

And, if you haven’t solved them (A LOT!), you’ll definitely make a stupid mistake somewhere or simply won’t have time.

It's like in sports - you need to repeat it many times to win for sure.

Find the collection wherever you want, necessarily with solutions, detailed analysis and decide, decide, decide!

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Find problems and solve them!

The table of powers contains the values ​​of positive natural numbers from 1 to 10.

Entry 3 5 read “three to the fifth power.” In this notation, the number 3 is called the base of the power, the number 5 is the exponent, and the expression 3 5 is called the power.

To download the table of degrees, click on the thumbnail image.

Degree calculator

We invite you to try our powers calculator, which will help you raise any number to a power online.

Using the calculator is very simple - enter the number you want to raise to a power, then the number - the power and click on the "Calculate" button.

It is noteworthy that our online degree calculator can raise both positive and negative powers. And for extracting roots there is another calculator on the site.

How to raise a number to a power.

Let's look at the process of exponentiation with an example. Suppose we need to raise the number 5 to the 3rd power. In the language of mathematics, 5 is the base, and 3 is the exponent (or simply the degree). And this can be written briefly as follows:

Exponentiation

And to find the value, we will need to multiply the number 5 by itself 3 times, i.e.

5 3 = 5 x 5 x 5 = 125

Accordingly, if we want to find the value of the number 7 to the 5th power, we must multiply the number 7 by itself 5 times, i.e. 7 x 7 x 7 x 7 x 7. Another thing is when you need to raise the number to a negative power.

How to raise to a negative power.

When raising to a negative power, you need to use a simple rule:

how to raise to a negative power

Everything is very simple - when raised to a negative power, we must divide one by the base to the power without the minus sign - that is, to the positive power. So to find the value

Table of powers of natural numbers from 1 to 25 in algebra

When solving various mathematical exercises, you often have to raise a number to a power, mainly from 1 to 10. And in order to quickly find these values, we have created a table of powers in algebra, which I will publish on this page.

First, let's look at the numbers from 1 to 6. The results here are not very large; you can check all of them on a regular calculator.

  • 1 and 2 to the power of 1 to 10

Table of degrees

The power table is an indispensable tool when you need to raise a natural number within 10 to a power greater than two. It is enough to open the table and find the number opposite the desired base of the degree and in the column with the required degree - it will be the answer to the example. In addition to the convenient table, at the bottom of the page there are examples of raising natural numbers to powers up to 10. By selecting the required column with powers of the desired number, you can easily and simply find the solution, since all powers are arranged in ascending order.

Important nuance! The tables do not show raising to the zero power, since any number raised to the zero power is equal to one: a 0 =1

Multiplication tables, squares and powers

It's time to do a little math. Do you still remember how much it is if two are multiplied by two?

If anyone has forgotten, there will be four. It seems that everyone remembers and knows the multiplication table, however, I discovered a huge number of requests to Yandex like “multiplication table” or even “download multiplication table”(!). It is for this category of users, as well as for more advanced ones who are already interested in squares and powers, that I am posting all these tables. You can even download for your health! So:

10 to the 2nd degree + 11 to the 2nd degree + 12 to the 2nd degree + 13 to the 2nd degree + 14 to the second degree/365

Other questions from the category

Help me decide please)

Read also

solutions: 3x(to the 2nd power)-48= 3(X to the 2nd power)(x to the second power)-16)=(X-4)(X+4)

5) three point five. 6) nine point two hundred seven thousandths. 2) write down the number in the form of an ordinary fraction: 1)0.3. 2)0.516. 3)0.88. 4)0.01. 5)0.402. 5)0.038. 6)0.609. 7)0.91.8)0.5.9)0.171.10)0.815.11)0.27.12)0.081.13)0.803

What is 2 to the minus 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 powers?

What is 2 to the minus 1 power?

What is 2 to the minus 2 power?

What is 2 to the minus 3 power?

What is 2 to the minus 4th power?

What is 2 to the power of minus 5?

What is 2 to the minus 6th power?

What is 2 to the minus 7th power?

What is 2 to the power of minus 8?

What is 2 to the minus 9th power?

What is 2 to the power of minus 10?

The negative power of n ^(-a) can be expressed in the following form 1/n^a.

2 to the power -1 = 1/2, if represented as a decimal fraction, then 0.5.

2 to the power - 2 = 1/4, or 0.25.

2 to the power -3= 1/8, or 0.125.

2 to the power -4 = 1/16, or 0.0625.

2 to the power -5 = 1/32, or 0.03125.

2 to the power - 6 = 1/64, or 0.015625.

2 to the power - 7 = 1/128, or 0.

2 to the power -8 = 1/256, or 0.

2 to the power -9 = 1/512, or 0.

2 to the power - 10 = 1/1024, or 0.

Similar calculations for other numbers can be found here: 3, 4, 5, 6, 7, 8, 9

The negative power of a number is, at first glance, a difficult topic in algebra.

In fact, everything is very simple - we carry out mathematical calculations with the number “2” using an algebraic formula (see above), where instead of “a” we substitute the number “2”, and instead of “n” we substitute the power of the number. The calculator will help to significantly reduce the time in calculations.

Unfortunately, the site's text editor does not allow the use of mathematical symbols for fractions and negative powers. Let's limit ourselves to capital alphanumeric information.

These are the simple numerical steps we ended up with.

A negative power of a number means that this number is multiplied by itself as many times as it is written in the power and then one is divided by the resulting number. For two:

  • (-1) degree is 1/2=0.5;
  • (-2) degree is 1/(2 2)=0.25;
  • (-3) degree is 1/(2 2 2)=0.125;
  • (-4) degree is 1/(2 2 2 2)=0.0625;
  • (-5) degree is 1/(2 2 2 2 2)=0.03125;
  • (-6) degree is 1/(2 2 2 2 2 2)=0.015625;
  • (-7) degree is 1/(2 2 2 2 2 2 2)=0.078125;
  • (-8) degree is 1/(2 2 2 2 2 2 2 2)=0,;
  • (-9) degree is 1/(2 2 2 2 2 2 2 2 2)=0,;
  • (-10) power is 1/(2 2 2 2 2 2 2 2 2 2)=0,.

Essentially, we simply divide each previous value by 2.

shkolnyie-zadachi.pp.ua

1) 33²: 11=(3*11)²: 11=3² * 11²: 11=9*11=99

2) 99²: 81=(9*11)²: 9²=9² * 11²: 9²=11²=121

The second degree means that the figure obtained during the calculations is multiplied by itself.

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Question: 5*4 to the second power -(33 to the second power: 11) to the 2nd power: 81 SAY THE ANSWER BY ACTION

5*4 to the second power -(33 to the second power: 11) to the 2nd power: 81 SAY THE ANSWER BY ACTION

Answers:

5*4²-(33²: 11)²: 81= -41 1) 33²: 11=(3*11)²: 11=3² * 11²: 11=9*11=99 2) 99²: 81=(9* 11)²: 9²=9² * 11²: 9²=11²=121 3) 5*4²=5*16=80 4)= -41

5*4 (2) = 400 1) 5*4= 20 2) 20*20=:11(2)= 9 1) 33:11= 3 2) 3*3= 9 The second power means that the number that turned out to be multiplied by itself during calculations.

10 to the -2 power is how much.

  1. 10 to the -2 power is the same as 1/10 to the 2 power, you square 10 and you get 1/100, which is equal to 0.01.

10^-2 = 1/10 * 1/10 = 1/(10*10) = 1/100 = 0.01

=) Dark you say? ..heh (from “White Sun of the Desert”)

  • 10 in -2 means 1 divided by 10 in 2. i.e. 0.01
  • 0.01 Finished your studies!
  • 10 to the 2nd power means 100

    10 to the 1st power 10

    if the degree is reduced by one, then the result decreases in this case by 10 times, therefore 10 to the power of 0 will be 1 (10/10)

    10 to the power of -1 is 1/10

    10 to the -2 power is 1/100 or 0.01

  • I didn’t understand what degree 2 or -2. if 2 before the answer is 100, if -2 then 0.01
  • 100, it’s strange how you think it turns out to be 0.01.
  • This is 0.01 - I am responsible for the correctness!! ! And the fact that they wrote you 100 is if it were 10 to the 2nd power, so you don’t even have to doubt it

    All this is ten to the minus second power

  • Is everything so difficult in the evening?

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