= sin^2 θ-2sinθcosθ-cos^2 θ
is this all?? what else can i do?
Not sure what you are trying to do but
Originally Posted by somanyquestions (sinθ-cosθ)^2
= sin^2 θ-2sinθcosθ+cos^2 θ
is this all?? what else can i do? two identities involved here ...
(1) the basic Pythagorean identity ...
(2) the double angle identity for sine ...