Solveeit Logo

Question

Question: The solution set of the inequality \(\log_{(\cos x)^{2}}{}\) (3 – 2x) \<\(\log_{(\cos x)^{2}}{}\) (...

The solution set of the inequality

log(cosx)2\log_{(\cos x)^{2}}{} (3 – 2x) <log(cosx)2\log_{(\cos x)^{2}}{} (2x – 1) is –

A

(12,1)\left( \frac{1}{2},1 \right)

B

(– ¥, 1)

C

(12,3)\left( \frac{1}{2},3 \right)

D

(1, ¥) – 2nπ\sqrt{2n\pi}"nÎN

Answer

(12,1)\left( \frac{1}{2},1 \right)

Explanation

Solution

\ 3 – 2x > 0 & 2x – 1> 0 for log to exist

x < 3/2 & x > 1/2 \ x Î (12,32)\left( \frac{1}{2},\frac{3}{2} \right) ...(1)

Now 0 < cos2x < 1

Take antilog

3 – 2x > 2x – 1 ̃ 4x < 1 ̃ x < 1 ...(2)

From (1) & (2) x Î(12,1)\left( \frac{1}{2},1 \right)