Prove the following identity:
What is the value of (Cos267o - sin2 23o)?
If 4 tan θ = 3, evaluate 4 sin θ - cos θ + 14 sin θ + cos θ - 1
If tan 2A = cot (A - 18o), where 2A is an angle, find the value of A
Prove that sin A - 2sin3 A2 cos3 A - cos A = tan A.
To Prove:
sin A - 2 sin3 A2 cos3 A - cos A = tan AL.H.S = sin A (1- 2 sin2 A)cos A (2 cos2 A -1)we know that, sin2 A + cos2 A = 1 = sin A cos A(sin2 A + cos2 A - 2 sin2 A)(2 cos2 A - sin 2 A - cos2 A) = tan A cos2 A - sin 2 Acos2 A - sin 2 A = tan A= R.H.S hence proved