Basic

Trigonometry uses the functions sine, cosine, and
sine, cosine, and tangent(abrev. sin, cos, tan). These functions are defined as follows:

• sin() = o / h
• cos() = a / h
• tan() = o / a

Where o represents the opposite side of the right triangle, a represents the adjacent, and h represents the hypotenuse.

Inverse

Just as many algebraic functions have inverses, these trigonometric functions also have inverse functions.
These functions are called arcsine, arccosine, and arctangent, what these functions do is take in the output of sine/cosine/tangent, and return the angle which was input.

Hyperbolic

These functions use the number e, which is the sum of the following infinite series:

and is roughly = 2.71828. They can be defined as follows: