Question

Sin cube theta + cos cube theta by sin theta + cos thetais equal to -1-cos theta sin theta

Answer 1

sin^3th +cos^3th/sin th + cos th

=(sin th +cos th)(sin^2 th -sin th .cos th + cos^2 th)/(sin th + cos th)

=(sin^2 th -sin th .cos th + cos^2 th)

=1-sin th.cos th

= RHS proved