Sum and Products Flashcards
1
Q
sinacosb
A
1/2[sin(a+b)+sin(a-b)]
2
Q
cosasinb
A
1/2[sin(a+b)-sin(a-b)]
3
Q
sinasinb
A
1/2[cos(a-b)-cos(a+b)]
4
Q
cosacosb
A
1/2[cos(a-b)+cos(a+b)]
5
Q
sinx + siny
A
2sin[(x+y)/2]cos[(x-y)/2]
6
Q
sinx - siny
A
2cos[(x+y)/2]sin[(x-y)/2]
7
Q
cosx + cosy
A
2cos[(x+y)/2]cos[(x-y)/2]
8
Q
cosx - cosy
A
-2sin[(x+y)/2]sin[(x-y)/2]