## Precalculus (6th Edition) Blitzer

$\left( f\circ g \right)\left( 0 \right)=-7$
Since the value of the given composite function can be obtained using the definition of composite functions and the values of $f$ and $g$ at the required points, t can be obtained very easily from the above equations. Now, $g\left( 0 \right)=4\left( 0 \right)-1=-1$ , thus we have \begin{align} & \left( f\circ g \right)\left( 0 \right)=f\left( g\left( 0 \right) \right) \\ & =f\left( -1 \right) \\ & =2\left( -1 \right)-5 \\ & =-7 \end{align}