Question

2cosx×cos 2x=cos x ,find x general solution​

Answer 1

Answer:

Given,

$2 \cos x \times \cos2x = \cos \: x$

$= > \cos2x = \frac{ \cos \: x}{2 \cos \: x}$

$= > \cos2x = \frac{1}{2}$

$= > \cos2x = \cos \: \frac{\pi}{3}$

Therefore, the general solution of cos is

$2x = 2n\pi \frac{ + }{} \frac{\pi}{3} , n € Z$

$= > x = \frac{2n\pi}{2} \frac{ + }{} \frac{\pi}{2 \times 3} , n € Z$

$= > x = n\pi \frac{ + }{} \frac{\pi}{6} , n € Z$

I hope this answer would be right.