Question

Find the value of x .
cos x = 2 sin 45° cos 45° – sin 30°​

Answer 1

Step-by-step explanation:

tan x = sin 45° X cos 45° + sin 30°

tan x = 1/√2 X 1/√2 + 1/2

tan x = 1/2 + 1/2

tan x = 1                                     → A

But,

tan 45° = 1                                  → B

From A & B, R.H.S. is equal,

∴ tan x = tan 45°

⇒      x = 45°

Answer 2

cos x = 2(1/√2)(1/√2)-1/2

cos x= 1-1/2

cos x =1/2

cos 60° = 1/2

Therefore, value of x is 60°