What is an exponent?
An exponent tells you how many times to multiply a base by itself. We write ab and say "a to the power b". For example, 2³ = 2 × 2 × 2 = 8. Exponents model repeated multiplication, growth, and are closely tied to logarithms (the inverse operation).
Rules of exponents
- Product: am × an = am+n
- Quotient: am / an = am−n (a ≠ 0)
- Power of a power: (am)n = amn
- Zero: a0 = 1 for a ≠ 0
Negative exponent explained
A negative exponent means take the reciprocal: a−n = 1 / an. Example: 10−2 = 1/100 = 0.01.
Fractional exponent explained
A fractional exponent is a root: a1/2 = √a, a1/3 = ∛a, and in general ap/q = (the q-th root of a)p for a ≥ 0 in the reals.
Examples
- 2³ = 8
- 5² = 25
- 10⁻² = 0.01
- 4^(1/2) = 2
- 27^(1/3) = 3