Question: Find the derivatives

(a) \(f\left( x \right)=-6{{e}^{-10{{x}^{4}}}}\); (b) \(f\left( x \right)=8{{e}^{x\sin x}}\); (c) \(f\left( x \right)=\sqrt[4]{\ln \left( 9-{{x}^{2}} \right)}\); (d) \(f\left( x \right)=\ln \left( {{\left( x+6 \right)}^{5}} \right)\)