Sums and Differences of Angles Flashcards
1
Q
cos(x-y)
A
cosx . cosy + sinx . siny
2
Q
cos(x+y)
A
cosx . cosy - sinx . siny
3
Q
sin(x+y)
A
sinx . cosy + siny . cosx
4
Q
sin(x-y)
A
sinx . cosy - siny . cosx
5
Q
tan(x+y)
A
(tanx + tan y) / (1 - tanx . tany)
6
Q
tan(x-y)
A
(tanx - tan y) / (1 + tanx . tany)
7
Q
sin2x
A
2 sinx . cosx
8
Q
tan2x
A
2 tanx / (1 - tan^2 x )
