Lesson 8-6B Use Cube Roots and Fractional Exponents After today’s lesson, you should be able to evaluate cube roots and simplify expressions with fractional exponents. (CA Alg 2.0)

Finding cube roots: Fractional Exponents (also called Rational Exponents) We have used radical signs to write square roots and cube roots. We can also write square roots and cube roots using fractional exponents.

Cube Roots

Square Roots

The Rule The rule for fractional exponents is that the numerator of the exponent is the power and the denominator is the root. ***The root of the base must be found before we can apply the power.

The Rule

Examples: Rewrite using radical notation.

You can also use fractional exponents when raising a radical to a power:

You can reverse this process to rewrite expressions containing fractional exponents into radical form.

We can now evaluate expressions containing rational exponents.