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Key Equations

Key Equations

arc length s=rθ s=rθ
area of a sector A= 1 2 θ r 2 A= 1 2 θ r 2
angular speed ω= θ t ω= θ t
linear speed v= s t v= s t
linear speed related to angular speed v=rω v=rω
Trigonometric Functions Sine sin t= opposite hypotenuse Cosine cos t= adjacent hypotenuse Tangent tan t= opposite adjacent Secant sec t= hypotenuse adjacent Cosecant csc t= hypotenuse opposite Cotangent cot t= adjacent opposite Sine sin t= opposite hypotenuse Cosine cos t= adjacent hypotenuse Tangent tan t= opposite adjacent Secant sec t= hypotenuse adjacent Cosecant csc t= hypotenuse opposite Cotangent cot t= adjacent opposite
Reciprocal Trigonometric Functions sin t= 1 csc t csc t= 1 sin t cos t= 1 sec t sec t= 1 cos t tan t= 1 cot t cot t= 1 tan t sin t= 1 csc t csc t= 1 sin t cos t= 1 sec t sec t= 1 cos t tan t= 1 cot t cot t= 1 tan t
Cofunction Identities cos t=sin( π 2 −t ) sin t=cos( π 2 −t ) tan t=cot( π 2 −t ) cot t=tan( π 2 −t ) sec t=csc( π 2 −t ) cos t=sin( π 2 −t ) sin t=cos( π 2 −t ) tan t=cot( π 2 −t ) cot t=tan( π 2 −t ) sec t=csc( π 2 −t )
Cosine cost=x cost=x
Sine sint=y sint=y
Pythagorean Identity cos 2 t+ sin 2 t=1 cos 2 t+ sin 2 t=1
Tangent function tant= sint cost tant= sint cost
Secant function sect= 1 cost sect= 1 cost
Cosecant function csct= 1 sint csct= 1 sint
Cotangent function cott= 1 tant = cost sint cott= 1 tant = cost sint