The value of cos2 48°– sin2 12° is

Given that, cos2 48°– sin2 12° = cos (48° + 12°) cos (48° – 12°)[∵cos2A – sin2B = cos (A + B) cos (A – B)]= cos60° cos36°

Q56 of 76 Page 52

The value of cos² 48°– sin² 12° is

Given that, cos² 48°– sin² 12° = cos (48° + 12°) cos (48° – 12°)

[∵cos²A – sin²B = cos (A + B) cos (A – B)]

= cos60° cos36°

The value of is given by

If A lies in the second quadrant and 3 tan A + 4 = 0, then the value of 2 cot A– 5 cos A + sinA is equal to

If then cos 2α is equal to

If then b cos 2θ + a sin 2θ is equal to