Please help me with a precalc assignment!
Given: A. sin(x) B. cos(x) C. cos(y) D. sin(y)
Use the drop-down menus in the derivation of the cosine sum identity:
sin(x + y)
= cos (StartFraction pi Over 2 EndFraction minus (x + y))
= Cosine ((StartFraction pi over 2 EndFraction minus x) minus y)
= Cosine (StartFraction pi Over 2 EndFraction minus x)
✔ C
+ Sine (StartFraction pi Over 2 EndFraction minus x)
A B C D
= sin(x)cos(y) + cos(x)sin(y)
