Trigonometric Identities Flashcards
1
Q
Sin^2 x + cos^2 x =
A
1
2
Q
Sin^2x=
A
1-cos^2 x
3
Q
cos^2 x =
A
1 - sin^2 x
4
Q
tan^2 x =
A
sec^2 x - 1
5
Q
sec^2 x =
A
tan^2 x +1
6
Q
cot^2 x =
A
csc^2 x -1
7
Q
csc^2 x =
A
cot^2 x + 1
8
Q
sin(α±β)=
A
sin(α)cosβ ± cos(α)sinβ
9
Q
cos(α±β)=
A
cos(α)cos β∓ sin(α)sinβ
10
Q
tan (α±β)=
A
(1∓ tan α tan β)
11
Q
sin2θ=
A
2sinθ cosθ
12
Q
cos 2θ=
A
cos^2θ - sin^2θ
and
2cos^2θ - 1
and
1 - 2sin^2θ
13
Q
tan2θ=
A
(1 - tan^2 θ)
14
Q
cos θ/2=
A
±√(1 + cosθ / 2)
15
Q
sin θ/2=
A
±√(1 - cosθ / 2)
