Double angle formulae Flashcards
1
Q
sin (2A)
A
2sinAcosA
2
Q
cos(2A)
A
cos^2 A - sin^2 A or 1-2sin^2 A
3
Q
tan(2A)
A
1 - 2tan A
4
Q
sin(A + B) =
A
sinA cos B + cos A sin B
5
Q
cos(A + B) =
A
cos A cos B — sin A sin B
6
Q
tan (A + B)
A
1 - tan A tan B
