Question:
The value of $\left[(81)^{\frac{1}{2}}\right]^{\frac{1}{2}}$ is
(a) 3
(b) $-3$
(C) 9
(d) $\frac{1}{3}$
Solution:
$\left[(81)^{\frac{1}{2}}\right]^{\frac{1}{2}}=\left[\left(3^{4}\right)^{\frac{1}{2}}\right]^{\frac{1}{2}}$
$=\left[3^{2}\right]^{\frac{1}{2}}$
$=3$
$\therefore$ The value of $\left[(81)^{\frac{1}{2}}\right]^{\frac{1}{2}}$ is 3
Hence, the correct option is (a).