My teacher never taught me how to find the index. i watched tons of videos but still don’t know how to solve this problem

SOLUTION
Recall that:
The index is the number outside the sqrt. (it’s 2 if it does not have a number).
The radical is the sqrt symbol.
The radicand is the number inside the sqrt symbol.
The given radical is:
[tex]\sqrt[4]{8}[/tex]Therefore, from the above definitions, the index is 4