What Are Fractional Exponents?
A fractional exponent (also called a rational exponent) is an exponent written as a fraction, like x^(2/3). Fractional exponents provide an alternative way to express roots: x^(1/n) = ⁿ√x (the nth root of x).
x^(a/b) = ᵇ√(xᵃ) = (ᵇ√x)ᵃ
x^(1/2) = √x (square root)
x^(1/3) = ³√x (cube root)
x^(2/3) = ³√(x²) = (³√x)²
Exponent Rules
- x^a × x^b = x^(a+b)
- x^a ÷ x^b = x^(a-b)
- (x^a)^b = x^(a×b)
- x^(-a) = 1/x^a
- x^0 = 1
How to Compute Fractional Exponents
To calculate x^(a/b): First take the b-th root of x, then raise to the a-th power. Or raise x to the a-th power first, then take the b-th root. Both give the same result.
Example: 8^(2/3) = (³√8)² = 2² = 4
How to Use
Enter the base number, numerator, and denominator of the fractional exponent. The calculator instantly computes the result.
Negative Bases
Negative bases with fractional exponents require care. If the denominator is even, the result is complex (not real). If odd, the result is real and negative.
Applications
Fractional exponents appear in physics (Kepler's laws), chemistry (reaction rates), economics (Cobb-Douglas functions), and throughout mathematics.