Question

If cos x = cos 40 sin 50 + sin 40 cos 50, then find the value of x.

Answer 1

Step-by-step explanation:

Given :

• cos x = cos 40° sin 50° + sin 40° cos 50°

Find :

• The value of x.

Solution :

sin 50° = sin (90° - 40°) = cos 40°

cos 50° = cos (90°- 40°) = sin 40°.

So,

➡ cos x = cos40° cos40° + sin 40° sin 40°

➡ cos x = cos² 40° + sin² 40° = 1

➡ cos x = cos 0°

➡ x = 0°.

Hence :

The value of x is 0°.

Answer 2

Answer:

therefore cosx = cos0

x=0

Step-by-step explanation:

cosx= sin(A+B)

cosx= sin90

cosx=1

cosx= cos0

x=0