Question

How do you find the domain & range for `f(x) = 2cos(4x + pi) -1`?

Answer 1

DOMAIN

The domain of definition of a function is represented by points on the x-axis where the function is defined.
Here, the function `f(x)` is defined for all real values of x, and hence the domain is the set of real numbers.

RANGE

The range of any cosine function (regardless of its argument) is `[-1,1]`

Thus the range for this function is:

`[2*(-1)-1,2*(1)-1]`

`=[-3,1]`