Angle Identities
What is the Reciprocal Identity of cot(x)
cos(x)/sin(x)
What is the Addition Formula for cos(α + β)?
cos(α)cos(β) - sin(α)sin(β)
What is the Addition Formula for cos(α - β)?
cos(α)cos(β) - sin(α)sin(β)
What is the Double-Angle Identity of cos2(x) (there are two of them)?
cos²(x) - sin²(x), 2cos²(x) - 1
What is the Reciprocal Identity of tan(x)
sin(x)/cos(x)
What is the Addition Formula for sin(α + β)?
sin(α)cos(β) + cos(α)sin(β)
What is the Addition Formula for sin(α - β)?
sin(α)cos(β) - cos(α)sin(β)
What is the Pythagorean Identity of 1?
sin²(x) + cos²(x)
What is the Pythagorean Identity of sec²(x)?
tan²(x) + 1
What is 180 deg. in radians?
π
What is 90 deg. in radians?
π/2
What is 60 deg. in radians?
π/3
What is 45 deg. in radians?
π/4
What is 30 deg. in radians?
π/6
What is the Half-Angle Identity of cos²(x)?
(1 + cos2(x))/2
What is the Half-Angle Identity of sin²(x)?
(1 - cos2(x))/2
What is the Double-Angle Identity of tan2(x) (there are two of them)?
(2tan(x))/(1 - tan²(x)), 1 - 2sin²(x)
What is the Addition Formula for tan(α + β)?
(tan(α) + tan(β))/(1 - tan(α)tan(β))
What is the Addition Formula for tan(α - β)?
(tan(α) - tan(β))/(1 + tan(α)tan(β))
What fractions/integers does π/4 (45°) equal to?
(√2)/2, (√2)/2
What fractions/integers does 7π/4 (315°) equal to?
(√2)/2, -(√2)/2
What fractions/integers does 11π/6 (330°) equal to?
(√3)/2, -1/2
What fractions/integers does π/6 (30°) equal to?
(√3)/2, 1/2
What fractions/integers does 3π/4 (135°) equal to?
-(√2)/2, (√2)/2
What fractions/integers does 5π/4 (225°) equal to?
-(√2)/2, -(√2)/2
What fractions/integers does 5π/6 (150°) equal to?
-(√3)/2, -1/2
What fractions/integers does 7π/6 (210°) equal to?
-(√3)/2, -1/2
What fractions/integers does π (180°) equal to?
-1, 0
What fractions/integers does 2π/3 (120°) equal to?
-1/2, (√3)/2
What fractions/integers does 4π/3 (240°) equal to?
-1/2, -(√3)/2
What is a sign identity equal to? For example: What is sin(-x) equal to (same method applies to cos, tan, csc, sec, and cot as well)?
-sin(x)
What fractions/integers does 3π/2 (270°) equal to?
0, -1
What fractions/integers does π/2 (90°) equal to?
0, 1
What is the Pythagorean Identity of csc²(x)?
1 + cot²(x)
What fractions/integers does 2π (360°) equal to?
1, 0
What fractions/integers does π/3 (60°) equal to?
1/2, (√3)/2
What fractions/integers does 5π/3 (300°) equal to?
1/2, -(√3)/2
What is the Reciprocal Identity of sec(x)
1/cos(x)
What is the Reciprocal Identity of csc(x)?
1/sin(x)
What is 330 deg. in radians?
11π/6
What is the Double-Angle Identity of sin2(x)?
2sin(x)cos(x)
What is 360 deg. in radians?
2π
What is 120 deg. in radians?
2π/3
What is 270 deg. in radians?
3π/2
What is 135 deg. in radians?
3π/4
What is 240 deg. in radians?
4π/3
What is 300 deg. in radians?
5π/3
What is 225 deg. in radians?
5π/4
What is 150 deg. in radians?
5π/6
What is 315 deg. in radians?
7π/4
What is 210 deg. in radians?
7π/6
