Question

sketch on cycle of cosine fuction

Answer 1

Well, you can use a graphing tool, but one way to understand it well is to plot some points.

Answer 2

Look at the unit circle. You have exact values for any trig function evaluation of \(0\), increments of \(\dfrac{\pi}{6}\), and increments of \(\dfrac{\pi}{4}\). So put those input angles on the x axis, and put the output values on the y axis (0 to 1 for cosine, so put 1 up high enough) and then play connect the dots.