Evaluate the following integrals

$($a$){\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}\frac{\sqrt[\phantom{2}]{9-x^2}}{x^2}dx$

$($b$){\displaystyle \underset{0}{\overset{1}{}}}\frac{1}{1+\sqrt[\phantom{2}]{x}}dx$