Question

when b>0 and d is a positive integer, (b)-2/d is equivalent to which of the following expression

Answer 1

the given exoression is

$=b^{-\frac{2}{d}}$

so,

$b^{-\frac{b}{2}}=\frac{1}{b^{\frac{2}{d}}}$$=\frac{1}{(\sqrt[d]{b})^2}$

thus, the correct answer is option A