Trigonometry Formulas/Identities 1 Flashcards
1
Q
Degrees to Radians
A
rad = degreesπ/180
2
Q
Radians to Degrees
A
degrees = rad(180/π)
3
Q
Area of a Sector (rad)
A
A=(θr^2)/2
4
Q
Area of a Sector (degrees)
A
A=(θπr^2)/2
5
Q
Arc Length (rad)
A
L=θr
6
Q
Arc Length (degrees)
A
L=(θπr)/360
7
Q
Angular Velocity
A
V= (total rad/degrees travelled)/total time
8
Q
Pythagorean Identity 1
A
sin^2θ+cos^2θ=1
9
Q
Pythagorean Identity 2
A
1+tan^2θ=sec^2θ
10
Q
Pythagorean Identity 3
A
1+cot^2θ=csc^2θ
11
Q
sin(x+y)=
A
sinxcosy+cosxsiny
12
Q
sin(x-y)=
A
sinxcosy-cosxsiny
13
Q
cos(x+y)=
A
cosxcosy-sinxsiny
14
Q
cos(x-y)=
A
cosxcosy+sinxsiny
15
Q
tan(x+y)=
A
(tanx+tany)/(1-tanxtany)
16
Q
tan(x-y)=
A
(tanx-tany)/(1+tanxtany)
17
Q
sin2x=
A
2sinxcosx
18
Q
cos2x=(both)
A
cos^2x-sin^2x
19
Q
cos2x=(cos)
A
2cos^2x-1
20
Q
cos2x=(sin)
A
1-2sin^2x
21
Q
tan2x=
A
2tanx/(1-tan^2x)
22
Q
sin(x/2)=
A
root((1-cosx)/2)
23
Q
cos(x/2)=
A
root((1+cosx)/2)
24
Q
tan(x/2)=
A
(1-cosx)/sinx
