Question

Sin teta +sin square teta =1 then prove that Cos square teta + cos power 4 teta =1

Answer 1

sin teta + sin^2 teta = 1 .

sin teta = 1 - sin^2 teta
sin teta= cos ^2 teta ...... then sin^2 teta = cos^4 teta

so, cos^2 teta + cos^4 teta
= cos^2 teta + sin ^2 teta
= 1