Question

Trying to figure how to factor:

Supposed to be solved on the interval [0,2pi)

sin(x-(pi/2))=cos(pi-x)

Answer 1

cos(a-b)=cos(a)cos(b)+sin(a)sin(b)

sin(a-b)=sin(a)cos(b)-sin(b)cos(a)

Answer 2

YOu mean not to factor, but to expand the sides.

Answer 3

Is there a table that gives those expansions? Or that I could look for in my math coursebook to study?