A radical equation has the variable under a root, like √(4t + 1) = 5. Square both sides, solve, then check, because squaring can create an extraneous solution. Rational exponents write roots as powers: 8^(2/3) = 4. An inverse function runs a rule backwards, swapping inputs and outputs, and exists only when no two inputs share an output. The square-root and cube-root graphs are the inverses of squaring and cubing.