# How do you use transformation to graph the cosine function and determine the amplitude and period of y=cos(-4x)?

Mar 26, 2018

Amp is 1
Period is $- \frac{\pi}{2}$

#### Explanation:

Acos(B(x-C)+D

A is the amplitude
period is $\frac{2 \pi}{B}$
C is the vertical translation
D is the horizontal translation

So amp in this case is 1

Period is $\frac{2 \pi}{-} 4 = - \frac{\pi}{2}$