trigonometry Flashcards
30° in radians
π/6
45° in radians
π/4
60° in radians
π/3
90° in radians
π/2
180° in radians
π
270° in radians
3π/2
360° in radians
2π
arc length formula
[radians]
rθ
area of a sector formula
[radians]
½ r²θ
area of a segment formula
[radians]
½ r² (θ - sinθ)
sin(π ⁄6)
½
sin(π ⁄3)
√3 ⁄2
sin(π ⁄4)
√2⁄ 2
cos(π ⁄6)
√3 ⁄2
cos(π ⁄3)
½
cos(π ⁄4)
√2 ⁄2
tan (π ⁄6)
√3 ⁄3
tan (π ⁄3)
√3
tan (π ⁄4)
1
what is sin θ small angle approximation
≈θ
what is cosθ small angle approximation
≈ 1 - θ² ⁄2
what is tanθ small angle approximation
≈ θ
how to convert from degrees to radians
converting degrees to radians you multiply by π/ 180
how to convert from radians to degrees
converting radians to degrees you multiply by
180/ π
what is the identity involving sin²x and cos²x
sin²x + cos²x = 1
in what way is cot x related to sinx and cos x
cot x is the inverse of tan x and the inverse of tan x is equal to cos x/ sin x
what is the identity involving cot²x and cosec²x
1 + cot²x =cosec²x
what is the inverse of sin x
1/ sin x = cosec x
what is the inverse of cos x
1/ cos x = sec x
what is the inverse of tan x
1/ tan x = cot x
area of a sector [degrees]
(θ/360º) × πr²
arc length [degrees]
2πr x (θ/360º)
area of a segment [degrees]
πr² x (θ/360º)
