Angles Flash Cards

Angle 30^o

A 30 degree angle is equal to π/6 radians

45^o degree angle in radians is

π /4 radians

60^o degree angle in radians is

π /3 radians

90^o degree angle in radians is

π /2 radians

270^o degree angle in radians is

3π/2 radians

π /3 radians Cos, Sin, Tan

• Cos: ½

• Sin: √3/2

• Tan: √3

π /6 radians Cos, Sin, Tan

• Cos: √3/2

• Sin: ½

• Tan: √3/3

π /4 radians Cos, Sin, Tan

• Cos: √2/2

• Sin: √2/2

• Tan: 1

3π /2 radians Cos, Sin, Tan

• Cos: 0

• Sin: -1

• Tan: Undefined

Reflection over y-axis

• Sin(π - θ) = sin(θ)

• Cos(π - θ) = - Cos(θ)

• Tan(π - θ) = - tan(θ)

Reflection over the x-axis

• Sin(2π - θ) = -sin(θ)

• Cos(2π - θ) = cos(θ)

• Tan(2π - θ) = -sin(θ)/cos(θ)

Reflection over the origin

• Sin(π + θ) = -sin(θ)

• Cos(π + θ) = -cos(θ)

• Tan(π + θ) = tan(θ)

Length of an Arc of a Circle Formula:

S = r _* θ where r is the radius (theta must be in RADIANS)

Area of a Sector Formula:

½ * (r)² * θ

• The answer A will always be to the power of 2.

Linear Speed Formula:

(V = s/t ) or (V = rθ / t) or (V = rω)

• s = length of arc or distance traveled

• t = time taken for the travel

• w = angular speed.

Circle of a radius Sin(t)

y/r or opp/hyp

Circle of a radius Cos(t)

x/r or adj/hyp

Circle of a radius tan(t)

y/x or sin/cos

Circle of a radius Sec(t)

r/x or 1/cos(t)

Circle of a radius Cot(t)

x/y or cos/sin of 1/tan(t)

Circle of radius Csc (t)

r/y

Unit circle csc(t)

1/y

Sec (t)

1/cos(t) or r/x

Unit of Circle Cot(t)

x/y