How do you graph #y=4cos(1/2x)#?

1 Answer
Oct 26, 2017

Answer:

Sketch the graph of #y=cos x# then stretch by a factor 2 in the #x#-direction and a factor 4 in the #y#-direction.

Explanation:

The #1/2# inside the cosine function causes a stretch of factor 2 in the #x#-direction and the 4 multiplying the cosine causes a stretch of factor 4 in the #y#-direction.
graph{y=cosx [-4.07, 8.414, -3.6, 2.64]}
graph{y=cos(x/2) [-4.07, 8.414, -3.6, 2.64]}
graph{y=4cos(x/2) [-4.07, 8.414, -3.6, 2.64]}