Question

prove that =(sun4teta+cos4teta/1-2sin2tetacos2teta=1​

Answer 1

Step-by-step explanation:

let the value of theta be x

To prove : sin4x + cos4x = 1 - 2sin2x cos2x

We have,

LHS = sin4x + cos4x

= (sin2x)2 + (cos2x)2 + 2sin2x cos2x - 2 sin2x cos2x   [By adding and subtracting 2sin2xcos2 x]

= (sin2x + cos2x)^2 - 2sin2x cos2x

= 1 - 2sin2xcos2x = RHS