# Stretching and Compressing Graphs of Trigonometric Functions

Here we will talk about graphing functions of the form y=msin(kx), y=mcos(kx), y=mtan(kx), y=mcot(kx).

Example. Draw graph of the function y=-3cos(2x).

Let's draw one half-wave of the graph y=cos(x). We first compress it with coeffcient 2 to y-axis and obtain graph of the function. Now, we stretch graph of the function y=cos(2x) with coeffcient 3 from x-axis and reflect result about x-axis. In result we will obtain one half wave of the function y=-3cos(2x). On a figure ileft graph is graph of the half-wave and right graph is all graph.