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Exponent is any number raised on a base which can also be seen as a numerical force meaning that the number is multiplied by itself. It is represented by a² where a is base and 2 is its power. This can be read as a raise to power 2. Therefore, the method of writing large numbers in a short form using exponent is known as the exponential form.
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Keyterms: Power, Exponent, Factor, Base, Number, Exponential form.
Powers and Exponents
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The expression that represents the repetition of the same factor is called power. For example, 5², which means 5 × 5 = 10. The number 5 is called the base, and the number 2 is called the power or exponent. The expectation corresponds to the number of times the base is used as a factor.

Powers and Exponents
Other examples, 42, 58, 77, 103, etc.
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Negative Exponents
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We know that positive exponents tell us how many times a number is multiplied by itself. Although, a negative exponent tells us how many times we have to multiply the reciprocal of the base number. In other words, a negative element explains how often we have to replicate the base.
An example of negative exponents is 5-4.
Therefore, it can be represented as 1/54.
After solving it we get 1/5 × 1/5 × 1/5 × 1/5 = 1/625.
More examples, 3-4, 2-6, 6-3, 5-7, 8-2, etc.
Note: If there is no exponent given in a number, its power is the same number which means it is its one time. For example, 2 - In this number, 1 is the power of 2 because 1 cannot be written in the power form.
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Laws of Exponent
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Some of the Laws of Exponents are described below.
Exponents with the same base
- When two exponential numbers are multiplied with the same base - N4 × N3= N(4+3)
- When two exponential numbers are divided with the same base - N4/ N3 = N(4-3)
Power of Powers
When a base has a power of power - (44)2, then the powers will be multiplied with each other. (44)2 = (4)4x2 = 48
Same Exponents but Different Bases
- When two numbers are multiplied with the same exponents - (44 × 24) = (4×2)4 = 84
- When two numbers are divided with the same exponents - (44 / 24) = (4/2)4 = 24
Also Read: Multiplication and Division of Integers
Use of Negative Exponents
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- Exponents are widely used in high-level calculations, which allow you to represent a number or variable that automatically repeats itself a certain number of times. For example, the expression 24 represents a product of 2 × 2 × 2 × 2, which is equal to 16.
- Some more applications include understanding the scientific scale as a pH scale or Richter scale, using a scientific note to write very large or very small numbers, and taking measurements.
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Things to Remember
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- The expression that represents the multiplication of the same number is called power.
- The negative exponent is defined as the multiplicative inverse of the base, raised to an exponent which is opposite the given exponent.
- a-2 is also known as the multiplicative inverse of a2.
- Powers are useful in expressing large expressions.
- A positive exponent determines how often we should multiply a base number, while a negative exponent determines how many times we should divide a base number.
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Sample Questions
Ques. Find the value of (i) 2-3 (ii) 2/3-4 (2 marks)
Ans. (i) 2-3= ½ × ½ × ½ = ?.
(ii) 2/3 = 3/2 × 3/2 × 3/2 × 3/2 = 81/ 16.
Ques. Simplify -: (3)6 × (3)-3 (2 marks)
Ans. (3)-6 × (3)3 = (3)-(6-3)
→ 3-3
→ 1/3 × 1/3 × 1/3
→ 1/27.
Ques. Evaluate (i) 3-3 (ii) (½)-4 (NCERT) (2 marks)
Ans. (i) 3-3 = 1/3 × 1/3 = 1/27
(ii) (½)-4 = 2 × 2 × 2 × 2 = 16
Ques. Express the following in exponents and powers - (a). 34500 (b). 1/25 (2 marks)
Ans. (a). 34500 = 345 × 100
→ 345 × 102
→ 3.45 ×102 ×102
(By dividing 345 by 100 and by shifting two decimal places to left and at the same
time multiplying by 100 or 102)
= 3.45 ×104.
(b). 1/25 = 1/52
= 5-2 (negative exponent)
Ques. Find the value of (i) 7-3 (ii) 46 (iii) (3/6)-6 (2 marks)
Ans. (i) 7-3 = 1/7 × 1/7× 1/7 = 1/343.
(ii) 46 = 4 × 4 × 4 = 64.
(iii) (3/6)-6 = 6/3 × 6/3 × 6/3 = 216/27.
Ques. (23 + 32)-3 (2 marks)
Ans. (23 + 32)-3 = (8 + 9)-3
→ 17-3
→ 1/17 × 1/17 × 1/17
→ 1/4913.
Ques. Simplify the following negative exponent - (2/3)-3 + (4)-2 (2 marks)
Ans. (2/3)-3 + (4)-2 = (3/2 × 3/2 × 3/2) + (¼ × ¼)
= (27/8) + (1/16)
= 54+1/16
= 55/16.
Simplify the expression - (23 ÷ 22)2 × 2-3 (2 marks)
Ans. (23 ÷ 22)2 × 2-3 = (2(3-2))² × 2-3
= (2)2 × 2-3
= 2(2-3)
= 2-1
= ½.
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