Question

2 cos squared theta = 3 cos theta -1 than find the volue of theta?​

Answer 1

Hey! Here is ur answer...

$2 {cos}^{2} \alpha = 3cos \alpha - 1 \\ 2 {cos}^{2} \alpha - 3cos \alpha + 1 =0 \\ 2 {cos}^{2} \alpha - 2cos \alpha - cos \alpha + 1 = 0 \\ 2cos \alpha (cos \alpha - 1) - 1(cos \alpha - 1) = 0 \\ (2cos \alpha - 1)(cos \alpha - 1) = 0 \\ cos \alpha = \frac{1}{2} \: and \: cos \alpha = 1 \\ \alpha = \frac{\pi}{3} \: and \: \alpha = \frac{\pi}{2 }$

Hope it helps u...☺