(sine is positive; Cosine right is positive; Tangent one three as evidence)
2kπ+α
π-α
π+α
2kπ-α
-α
commit a crime
sinα
sinα
-sinα
-sinα
-sinα
cosine
Coase α
-cosα
-cosα
Coase α
Coase α
Dark color
tanα
-tanα
tanα
-tanα
-tanα
(π/2)-α
(π/2)+α
(3π/2)-α
(3π/2)+α
commit a crime
Coase α
Coase α
-cosα
-cosα
cosine
sinα
-sinα
-sinα
sinα
Dark color
cotα
-cotα
cotα
-cotα
Two: sine, cosine and tangent of the sum and difference of two angles.
sin(α+β)=sinαcosβ+cosαsinβ
sin(α-β)=sinαcosβ-cosαsinβ
cos(α+β)=cosαcosβ-sinαsinβ
cos(α-β)=cosαsinβ+sicαcosβ
tan(α+β)=(tanα+tanβ)/( 1-tanαtanβ)
tan(α-β)=(tanα-tanβ)/( 1+tanαtanβ)
Three: auxiliary angle formula
asinx+bconx=(√a？ +b？ )×sin(x+γ)
Note: γ=tan(b/a)
Four: Double Angle Formula
sin2α=2sinαcosα
cos2α=cos？ α-sin？ α= 1-2sin？ α=2cos？ α- 1
tan2α=2tanα/( 1-tan？ α)
Five: the basic relationship of trigonometric functions
Sin? αcos？ α= 1
tanα=sinα/cosα
tanαcotα= 1
That's about it. I hope I can help you.