Question

sin^4theta +cos^4theta​

Answer 1

Step-by-step explanation:

sin 4 theta - cos4 theta

=( sin2 theta)2-( cos2 theta)2

(a2-b2) =(a+b)(a-b)

= (sin2theta -cos 2theta)(sin2theta+ cos2theta)

=(sin2theta- cos2theta) *1

= -( cos2 thete- sin2 theta )

( as cos2 theta- sin2theta= cos 2A)

=. - cos2 theta