Question

Find the range of y = 3cos4x - 2.

-5 ≤ y ≤ 5
-5 ≤ y ≤ 1
-3 ≤ y ≤ 3
1 ≤ y ≤ 3

Answer 1

ANSWER

$- 5\leqslant y \leqslant 1$

EXPLANATION

The given cosine function is:

$y = 3 \cos4x - 2$

The amplitude of this function is:

3

This means the parent function has range:

$- 3 \leqslant y \leqslant 3$

The given function has been shifted down by 2 units.

So we add -2 to the peak values to get

$- 2 + - 3 \leqslant y \leqslant 3 + - 2$

The given function has range:

$- 5\leqslant y \leqslant 1$

Answer 2

Answer:

-5 ≤ y ≤ 1

Step-by-step explanation:

correct