Question $2$

Find the first derivative $of$ each $of$ the following functions:

$(a)f(x)={\displaystyle \underset{1}{\overset{x^3}{}}}costdt$

$(b)h(x)={\displaystyle \underset{-x}{\overset{\sqrt[\phantom{2}]{x}}{}}}\sqrt[\phantom{2}]{v^2+2}dv$

$(c)g(x)={\displaystyle \underset{1-3x}{\overset{1}{}}}\frac{u^3}{1+u^2}du$