Section 1
Precalculus Review
By Boundless
![Thumbnail](../../../../../../figures.boundless-cdn.com/17996/square/three-dimensional-graph.jpg)
Functions relate a set of inputs to a set of outputs such that each input is related to exactly one output. Graphs can be used to represent these relationships pictorially.
Linear and quadratic functions make lines and a parabola, respectively, when graphed and are some of the simplest functional forms.
![Thumbnail](../../../../../../figures.boundless-cdn.com/17999/raw/unitcircledefs.jpg)
Trigonometric functions are functions of an angle, relating the angles of a triangle to the lengths of the sides of a triangle.
![Thumbnail](../../../../../../figures.boundless-cdn.com/18002/square/inverse-function.jpg)
An inverse function is a function that undoes another function: For a function
![Thumbnail](../../../../../../figures.boundless-cdn.com/18003/raw/exp-tangent.jpg)
Both exponential and logarithmic functions are widely used in scientific and engineering applications.
![Thumbnail](../../../../../../figures.boundless-cdn.com/18005/square/ti-84-plus-graphing.jpeg)
For numerical calculations and graphing, scientific calculators and personal computers are commonly used in classes and laboratories.