Question

if sin theta + sin²theta = 1 , then proof cos² theta + cos ⁴ theta = 1​

Answer 1

Answer:

sin theta + sin² theta = 1

sin theta = 1 - sin² theta

sin theta = cos² theta

now, cos² theta + cos⁴ theta = 1

cos ² theta + (cos² theta)² = 1

substitute sin theta = cos² theta

sin theta + sin² theta = 1 (given)

hence, proved