Discussion Forum



1)

The range of the function f (x) = $\frac{1}{2-cos3x}$ is


A) (-2, 8)

B) [-2,3]

C) [1/3, 1]

D) (1/2,1)

Answer:

Option C

Explanation:

We have - 1≤ cos 3x≤ 1 = - 1 ≤-cos 3x≤ 1

Add '2' on both sides

1≤ 2 - cos 3x ≤ 3

1 ≥ $\frac{1}{2-cos3x}$ ≥ 1/3