Question

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

Answer 1

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(x)=cosax`, the amplitude remains unchanged (`<-1;1>`), but the period changes to `T=(2pi)/a`. In this case the period is `4`