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Power & Root Calculator Guide: Exponents and Roots Explained

Powers and roots are inverse operations — fundamental to compound interest, physics, and engineering. Understanding them unlocks most of advanced mathematics.

Powers Reference Table

Base² (Square)³ (Cube)
2481632
392781243
416642561,024
5251256253,125
101001,00010,000100,000

Exponent Laws

Product rule
aᵐ × aⁿ = aᵐ⁺ⁿ
2³ × 2⁴ = 2⁷ = 128
Quotient rule
aᵐ ÷ aⁿ = aᵐ⁻ⁿ
3⁵ ÷ 3² = 3³ = 27
Power rule
(aᵐ)ⁿ = aᵐˣⁿ
(2³)² = 2⁶ = 64
Zero exponent
a⁰ = 1
7⁰ = 1, 100⁰ = 1
Negative exponent
a⁻ⁿ = 1/aⁿ
2⁻³ = 1/8 = 0.125
Fractional exponent
a^(1/n) = ⁿ√a
8^(1/3) = ∛8 = 2

Frequently Asked Questions

What is a power (exponent)?

A power means multiplying a number by itself a specified number of times. bⁿ = b × b × b... (n times). For example, 2⁵ = 2×2×2×2×2 = 32. The base is 2, the exponent is 5.

What is a square root?

The square root of a number n is the value that, when multiplied by itself, gives n. √n = x means x² = n. For example, √144 = 12 because 12² = 144. Every positive number has two square roots: one positive and one negative.

What is an nth root?

The nth root of a number is the value that, when raised to the power n, gives the original number. The cube root ∛8 = 2 because 2³ = 8. The 4th root ∜81 = 3 because 3⁴ = 81.

What is a negative exponent?

A negative exponent means reciprocal. b⁻ⁿ = 1 ÷ bⁿ. For example, 2⁻³ = 1 ÷ 2³ = 1/8 = 0.125. Any non-zero number raised to the power 0 equals 1: b⁰ = 1.

What is a fractional exponent?

A fractional exponent represents a root. b^(1/n) = n√b. For example, 8^(1/3) = ∛8 = 2. And b^(m/n) = (n√b)^m. So 8^(2/3) = (∛8)² = 2² = 4.

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