vOCABULARY Rewrite the expression \( a^{-s i t} \) in radical form. Then state the index of the radical. \( a^{-s t} \) written in radical form is \( \frac{1}{a \frac{s}{t}} \times \). The index of the radical is \( \square \).

The expression \( a^{-s t} \) in radical form can be rewritten as \( \frac{1}{\sqrt[st]{a}} \). Here, we're taking the reciprocal of the radical, which is why we have that \( \frac{1}{\sqrt[st]{a}} \) format in place. The index of the radical, which tells us the degree of the root, is \( s t \). Think of it like this: if you have the square root, the index is 2; with a cube root, it's 3. Here, the index is precisely \( st \), making it as significant as the roots themselves!