# What is the range of #y = -2 cos 3x#?

##### 1 Answer

Mar 30, 2018

#### Explanation:

We have to know the range of a normal

We next have to know what the translation form of cosine graphs looks like

A~Amplitude, stretches all the y values by A

B~Period, stretches the period by

C~ vertical translation, moves the x values across by C

D~ horizontal translation, moves the y values up D

So A and D effect the range and B and C effect the domain

So from this we know the y values have been stretched by -2 so the range becomes -2 and 2