Formulas of trigonometric functions:

Sine: The opposite side of angle α is the hypotenuse.

Cosine (cos): The adjacent side of angle α is higher than the hypotenuse.

Tangent (tan): The opposite side of angle α is greater than the adjacent side.

Cotangent: The adjacent side of angle α is greater than the opposite side.

Secant: The hypotenuse of angle α is higher than the adjacent side.

Cotangent: The hypotenuse of angle α is higher than the edge.

Equidistant trigonometric function:

Square relation:

sin^2(α)+cos^2(α)= 1。

tan^2(α)+ 1=sec^2(α)。

cot^2(α)+ 1=csc^2(α)。

Product relationship:

sinα=tanαcosαcosα=cotαsinα.

tanα=sinαsecαcotα=cosαcscα.

secα=tanαcscαcscα=secαcotα.