Cos^3(x)+sin^2(x)*cos(x)=cos(x)

Question

Verify the left side equals the right side

 

Answer 1

cos^3x+sin^2xcosx=cosx

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

cos^2x+sin^2x=1  (trig identity)

cosx(1)=cosx

cosx=cosx