Review: Angle Sum and Difference, Half Angle and Double Angle Formulas Flashcards
1
Q
cos(α-β)
A
cosα*cosβ+sinα*sinβ
2
Q
cos(α+β)
A
cosα*cosβ-sinα*sinβ
3
Q
sin(α+β)
A
sinα*cosβ+sinβ*cosα
4
Q
sin(α-β)
A
sinα*cosβ-sinβ*cosα
5
Q
tan(α+β)
A
(tanα+tanβ)/(1-tanα*tanβ)
6
Q
tan(α-β)
A
(tanα-tanβ)/(1+tanαtanβ)
7
Q
sin2α
A
2sinα*cosα
8
Q
tan2α
A
2tanα/(1 - tan²α)
9
Q
cos2α
A
= cos²α-sin²α
= 2cos²α-1
= 1-2sin²α
10
Q
cos α/2
A
±√((1+cosα)/(2))
11
Q
sin α/2
A
±√((1-cosα)/(2))
12
Q
tan α/2
A
±√((1-cosα)/(1+cosα))
