## Precalculus (6th Edition) Blitzer

When the input of the function $f\left( x \right)$ changes to $f\left( x+a \right)$ the graph of the function $f\left( x \right)$ is shifted to the left by $a$ units. Again, if the function $f\left( x \right)$ is changed to $f\left( x \right)+b$ the graph of the function $f\left( x \right)$ is shifted up by $b$ units. The above graph has a maximum value of 4 at $-2$. The graph is never zero since it does not cross or touch the x-axis.