Trigonometric Identities Flashcards
1
Q
How to convert degrees to radians…
A
- (πrad/180º)
2
Q
How to convert radians to degrees…
A
- (180º/πrad)
3
Q
Reciprocal: sinθ=
A
1/cscθ
4
Q
Reciprocal: cosθ=
A
1/secθ
5
Q
Reciprocal: tanθ=
A
1/cotθ
6
Q
Reciprocal: cscθ=
A
1/sinθ
7
Q
Reciprocal: secθ=
A
1/cosθ
8
Q
Reciprocal: cotθ=
A
1/tanθ
9
Q
Pythagorean theorem
A
- (sinθ)^2 + (cosθ)^2 = 1
- 1 + (tanθ)^2 = (secθ)^2
- 1 + (cotθ)^2 = (cscθ)^2
10
Q
Arc length
A
s=rθ (where θ is in radians only)
11
Q
Sector area
A
A=(1/2)(r^2)(θ) (where θ is in radians only)
12
Q
Cofunction of sin(90º-θ)
A
cosθ
13
Q
Cofunction of cos(90º-θ)
A
sinθ
14
Q
Cofunction of tan(90º-θ)
A
cotθ
15
Q
Cofunction of cot(90º-θ)
A
tanθ
