Double Angle Formulae Flashcards
1
Q
sin90
A
1
2
Q
tan90
A
undefined
3
Q
cos90
A
0
4
Q
tan0
A
0
5
Q
sin0
A
0
6
Q
cos0
A
1
7
Q
sin2x
A
2sinxcosx
8
Q
cos2x
A
- cos^2x-sin^2x
- 1-2sin^2x
- 2cos^2x-1
- 1-tan^2x/1+tan^2x
9
Q
tan2x
A
(2tanx)/(1-tan^2x)
10
Q
cos(A-B)
A
cosAcosB+sinAsinB
11
Q
cos(A+B)
A
cosAcosB-sinAsinB
12
Q
sin(A-B)
A
sinAcosB-cosAsinB
13
Q
sin(A+B)
A
sinAcosB+cosAsinB
14
Q
tan(A+B)
A
tanA+tanB/1-tanAtanB
15
Q
tan(A-B)
A
tanA-tanB/1+tanAtanB
16
Q
sin^2x+cos^2x
A
1
17
Q
For theta in radians
A
l=thetar
A=1/2 thetar^2
18
Q
For theta in degrees
A
l=theta/360 *2πr
A=theta/360 * πr^2
19
Q
sinx
A
sin(π-x)
20
Q
cosx
A
cos(2π-x)
21
Q
tanx
A
tan(x+π)
22
Q
Area of a triangle
A
S=1/2 ab sinc
