Trigonometry Flashcards
1
Q
2pi
A
360 degrees
2
Q
pi
A
180 degrees
3
Q
pi/2
A
90 degrees
4
Q
pi/3
A
60 degrees
5
Q
pi/4
A
45 degrees
6
Q
pi/6
A
30 degrees
7
Q
sin theta (small angle approx)
A
theta
8
Q
cos theta (small angle approx)
A
(1 - theta^2) / 2
9
Q
tan theta (small angle approx)
A
theta
10
Q
sin30
A
1/2
11
Q
cos30
A
root3 / 2
12
Q
tan30
A
1 / root3
13
Q
sin60
A
root3 / 2
14
Q
cos60
A
1 / 2
15
Q
tan60
A
root3
16
Q
sin45
A
1/ root2
17
Q
cos45
A
1 / root2
18
Q
tan45
A
1
19
Q
tan theta definition
A
sin theta / cos theta
20
Q
cosec x
A
1/sinx
21
Q
sec x
A
1/cosx
22
Q
cotx
A
1/tanx
23
Q
sinx co-function
A
cos(90-x)
24
Q
cosx co-function
A
sin(90-x)
25
Pythagorean identities
sin^2 x + cos^2 x = 1
1 + tan^2 x = sec^2 x
1 + cot^2 x = cosec^2 x
26
sin(A+-B)
sinAcosB +- sinBcosA
27
cos(A+-B)
cosAcosB -+ sinAsinB
28
tan(A+-B)
(tanA +- tanB) / (1 -+ tanAtanB)
29
sin2x
2sinxcosx
30
cos2x
2 cos^2 x - 1 OR 1 - 2 sin^2 x OR cos^2 x - sin^2 x
31
tan2x
(2tanx)/(1-tan^2x)
32
sin^2 x (Double angle)
1/2 - 1/2 cos2x
33
cos^2 x (Double angle)
1/2 + 1/2 cos 2x
34
If Rcosx = a, Rsinx = b:
R = root(a^2 + b^2), tanx = b/a
