Question

How do you find the domain and range for `y = 3 cos 4x`?

Answer 1

Domain: `x=`all real numbers
Range: `[-3,3]` or `-3<=x<=3`

Explanation:

Domain: `x=`all real numbers (normal cos function so no domain restrictions.)
Range: `[-3,3]` or `-3<=x<=3` (Amplitude is 3.)