Question

(sinx+cosx)[kwadrat]=1+2sinxcosx

Answer 1

( sin x + cos x )^2 = sin ^2 x + 2 sin x*cos x + cos^2 x =

= sin^2 x + cos ^2 x + 2 sin x *cos x= 1 + 2 sin x * cos x

bo

sin ^2 x + cos ^2 x = 1