By Graphing the Function $$f ( x ) = \frac { ( \cos x - \cos 5 x ) } { x ^ { 2 } }$$

Short Answer

By graphing the function $$f ( x ) = \frac { ( \cos x - \cos 5 x ) } { x ^ { 2 } }$$
and zooming in toward the point where the graph crosses the $y$ -axis, estimate the value of $\lim _ { x \rightarrow 0 } f ( x )$ .