Question

cos2x =cos 60×cos30 +sin60 × sin30​

Answer 1

Answer:

x=15°

Step-by-step explanation:

cos 2x = cos60°×cos 30° + sin60°×sin30°

cos 2x = cos(60°-30°)

cos 2x = cos 30°

2x = 30°

x = 15°

cos 2x = cos 30° = √3\2