Evaluate the following improper integrals.

$($a$){\displaystyle \underset{-}{\overset{}{}}}\frac{dx}{(1ta{n}^{-1}(x))(1x^2)}$

$($b$){\displaystyle \underset{-1}{\overset{5}{}}}\frac{dx}{\sqrt[\phantom{2}]{|x|}}$