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

Oct 26, 2017

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 $\frac{1}{2}$ 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]}