Quiz 8: Sum Product Formulas
Name:
sin(x + y) = sin x cos y + cos x sin y
cos(x + y) = cos x cos y − sin x sin y
Use the sum formulas above to simplify each sum to a product:
0. sin(x + y) − sin(x − y) =
= sin x cos y + cos x sin y
− sin x cos y − cos x sin y
= 2 cos x sin y
1. sin(x + y) + sin(x − y) =
2. cos(x + y) + cos(x − y) =
3. cos(x + y) − cos(x − y) =