Transformation formula of trigonometric function sin(-α)=-sinα.
cos(-α)=cosα
sin(π/2-α)=cosα
cos(π/2-α)=sinα
sin(π/2+α)=cosα
cos(π/2+α)=-sinα
Sine (π-α) = Sine α
cos(π-α)=-cosα
Sine (π+α) =-Sine α
tanα=sinα/cosα
tan(π/2+α)=-cotα
tan(π/2-α)=cotα
tan(π-α)=-tanα
tan(π+α)=tanα
Formulas of trigonometric functions of right angle sine: sinA=a/c (that is, the opposite side of angle A is more than the hypotenuse).
Cosine: cosA=b/c (that is, the adjacent side of angle A is more than the hypotenuse).
Tangent: tanA=a/b (that is, the opposite side of angle A is closer to the adjacent side)
Cotangent: cotA=b/a (that is, the adjacent edges of angle A are compared with each other).
SecA=c/b (that is, the hypotenuse of angle A is adjacent to the edge).
Cotangent: cscA=c/a (that is, the hypotenuse of angle A is compared with the edge)