## Precalculus (6th Edition) Blitzer

The function $h\left( x \right)$ can be written as a composition of the functions $f\left( x \right)={{x}^{4}}\text{ and }g\left( x \right)={{x}^{2}}+2x-1$.
Consider the functions $f\left( x \right)={{x}^{4}}$ and $g\left( x \right)={{x}^{2}}+2x-1$. Then, \begin{align} & h\left( x \right)={{\left( {{x}^{2}}+2x-1 \right)}^{4}} \\ & =f\left( g\left( x \right) \right) \end{align} Hence, the function x can be written as a composition of the above functions.