Chapter 11 - Quadratic Functions and Equations - 11.6 Quadratic Functions and Their Graphs - 11.6 Exercise Set - Page 741: 78

Instead of shifting the graph of $f(x)$ by $h$ units to the right, we shift it to the left.

If $h$ is positive, then the graph of $f(x-h)$ is obtained by shifting the graph of $f(x)$ by $h$ units to the right. If $h$ is negative, then the graph of $f(x+h)$ is obtained by shifting the graph of $f(x)$ by $h$ units to the left.