Question

Please help me idk how to solve it.
Simplify: (sin Θ − cos Θ)2 − (sin Θ + cos Θ)2

−4sin(Θ)cos(Θ)
2
sin2 Θ
cos2 Θ

Answer 1

$(sinФ-cosФ)^2-(sinФ+cosФ)^2$

sin^2Ф+cos^2Ф-2sinФcosФ-(sin^2Ф+cos^2Ф+2sinФcosФ)
1-2sinФcosФ-1-2sinФcosФ
we know sin^2Ф+cos^2Ф=1

-4sinФcosФ
answer is A