IB Mathematics SL/Circular Functions and Trigonometry
Topic 3: Circular Functions and Trigonometry
Length of an arc
The length of an arc is equal to s=r(theta), where r= radius, (theta)=inscribed angle in radians, and s=the length of the arc.
This formula is synonymous with the formula for the circumference of a circle where (theta)=2(pi).
Area of a Sector
A = (1/2)(θ)(r(squared)) where r is the radius.
Cosine and Sine (relative to Unit Circle)
sinθ=y cosθ=x tanθ=y/x CAST Beginning from the IV section will let you know which are positive (Cosine, All, Sine, Tangent)
Double Angle Formulae
cos2(θ)= cos^2(θ)-sin^2(θ)= 2cos^2(θ)-1=1-2sin^2(θ)
Area of a triangle = (1/2) ab sin C