Question

prove that sin^4 x + cos^4x=1-2 cos^2 +2 cos^4x​

Answer 1

Answer:

sin⁴x - cos⁴x

= (sin⁴x - cos⁴x) factor

= sin²x - cos²x) -1

= (1 - cos²x ) - cos²x use the property

= sin² x + cos²x = 1

= 1 - 2 cos²x