Find the 3 smallest positive x-intercepts of the graph of

y = cos(12x) + cos(16x) + cos(20x)

and list them in increasing order.

Guest Feb 13, 2022

#1**+1 **

Do you know what y=cos(x) looks like?

Graph it on desmos if you do not know..

What is its period?

Where does it first cross the x axis?

https://www.desmos.com/calculator/xbk6uv697u

Try drawing cos(12x) how does it compare?

Try drawing them, discuss it here, if you have specific questions then ask with a new post on this thread.

Melody Feb 13, 2022