Question

How do you graph `y=4cos2(x-pi)+1`?

Answer 1

The graph is a cosine wave about y = 1, with amplitude = 4, period = `pi`. The graph is inserted.

Explanation:

`y-1=4cosx(x-pi)=4cos(2x-2pi) =4cos(2pi-2x)=4cos2x`.

This represents a cosine wave about y - 1. The period is `(2pi)/2=pi`

and the amplitude about y = 1 is 4.

Graph is inserted. Here, `pi=3.14`, nearly. Look for graph for one

period with `in [-pi/2, pi/2]=[-1.57, 1.57]` Correspondingly, y reaching

crest y = 5 twice and minimum y =-3 also twice at the ends.

graph{y-1-4cos(2x)=0 [-10, 10, -5, 5]}