Question

(vii)
sin A - 2 sin³A/
2 cosA - cosA= tanA​

Answer 1

Step-by-step explanation:

sin A - 2 Sin^3A/2cos^3A - CosA = Tan A

Sin A ( 1 - 2Sin^2A)/ CosA(2cos^2A - 1)

2Cos^2A - 1 = 2(1- sin^2A) - 1                    [1 - Sin2^A = Cos^2A]

= 2 - 2Sin^2A -1

= 1 - 2Sin^2A

hence 1 - 2Sin^2A = 2cos^2A - 1

Now, we can cancel then after cancelling we get,

SinA/CosA = TanA                                   [SinA/CosA = tanA]

Hence Proved