Question

Prove the following:

Answer 1

Step-by-step explanation:

(2cos^2A -1)^2 + 3(1- 2sin^2A)

If we look both of them correctly

we can observe that they are formulas of Cos2A

so,

(Cos2A)^3 + 3 (Cos2A) = L.H.S

R.H.S = 4 ( cos^6A - sin^6A)

= (Cos2A )^3 +3( Cos2A)

(Cos2A = cos^2A - sin^2A)

Therefore L.H.S = R.H.S