Question

sin(П/2-а)-sin(П-а)-cos(П-а)-sin(2П-а)

Answer 1

$sin( frac{pi}{2}-alpha)-sin( pi-alpha)-cos(pi-alpha)-sin(2pi-alpha) \ \ cos(alpha)-sin(alpha)-(-cos(alpha))-(-sin(alpha)) \ \ cos(alpha)-sin(alpha)+cos(alpha)+sin(alpha) =2cos(alpha)$