Homework resources in Trigonometric Equations - Trigonometry - Math. This trigonometry laws and identities help sheet contains the law of cosines, law of sines, and law of tangents. Trigonometry is the study of triangles, which contain angles, of course. Get to know some special rules for angles and various other important functions, definitions, and translations. Sines and cosines are two trig functions that factor heavily into any study of trigonometry; they have their own ... Free math lessons, formulas, calculators and homework help, in calculus, algebra, analytic geometry and linear algebra. Arc(Length(= Arc Length = Central angle (in Radians) r = radius Sr S θ θ = g! Cofunctions((sinJcos,(secJcsc,(tanJcot)(! Cofunctions!of! Complementary!Angles!are!