# How do you graph y = cos (pi /2) x?

Sep 5, 2015

The graph looks like:

graph{cos(pi/2*x) [-1.004, 6.79, -1.715, 2.18]}

#### Explanation:

When you draw a graph of a function $f \left(x\right) = \cos a x$, the amplitude remains unchanged (<-1;1>), but the period changes to $T = \frac{2 \pi}{a}$. In this case the period is $4$