5. Radians Flashcards
180 and 360 degrees in radians
π and 2π
Degrees to radians conversions
Divide by 180 and times by π
Radians to degrees conversion
Divide by π and multiply by 180
How to get into radians mode
Shift, set up, find deg, F2
CAST diagrams for radians
Work exactly the same, just replace 180 and 360 with π and 2π
Use to find exact values
Angle in radians formula
Arc length/ radius
Arc length formula
rθ
Where θ is the central angle measured in radians
Perimeter of a sector
θr + 2r
Where θ is the central angle measured in radians
Radius from perimeter of a sector
r = P/(2+θ)
Where P is the perimeter of the sector and θ is the central angle measured in radians
Sector Area
A = 1/2 r^2 θ
Where θ is the angle in radians
A sector is a part of a circle formed by two radii and an arc
Segment Area
A = 1/2r^2 (θ - sin(θ))
Where θ is the angle of the sector containing the segment in radians
A segment is the region between a chord and the circumference
Minor Sector
The sector such that it contains less than half of the circle
Sin θ when θ is a small angles measured in radians
Sin(θ) ≈ θ
Tan θ when θ is a small angles measured in radians
Tan(θ) ≈ θ
Cos θ when θ is a small angles measured in radians
1- ((θ)^2/2)
