An "identity" is a tautology, an equation or statement that is always true, no matter what. Proving an identity is very different in concept from solving an equation. This resource demonstrates some useful techniques for proving...

Explains a simple pictorial way to remember basic reference angle values. Provides other memory aids for the values of trigonometric ratios for these "special" angle values, based on 30-60-90 triangles and 45-45-90 triangles.

This resource provides an overview of graphing, giving examples of general polynomial, radical, rational, and piecewise functions. Also includes advice on common mistakes made by students.

This resource covers negative exponents and demonstrates how to simplify expressions containing them. Explains why "to the power zero" means "equals 1".A negative exponent just means that the base 'x' is on the wrong side of the fraction...

Defines the Pythagorean Theorem, and demonstrates how to use this Theorem in connection with right-angled triangles.

Explains how to model angles in the x,y-plane, and demonstrates how to extend the concept of trig ratios to angles larger than 90 degrees.

Explains formulas for areas of sectors of circles and lengths of arcs. Demonstrates how to use the formulas in each of degrees and radians.

You know that you can take side lengths and find trig ratios, and you know you can find trig ratios (in your calculator) for angles. What is missing is a way to go from the ratios back to the original angles. And that is what "inverse...

Introduces the basic terminology of Venn diagrams, and shows how to "populate" and read Venn diagrams.

This resource provides a description and examples of how to convert between two units.

Gives a detailed explanation of how the order of operations works. Explains how to use the PEMDAS acronym (Parenthesis, Exponents, Multiplication, Division, Addition, Subtraction) to remember the correct order. Includes lots of example...

Scroll down to just below the middle of the lesson for an in-depth lesson on converting fractions to percents. Works through numerous examples step by step and shows what happens when the "decimal expansion" doesn't end when converting.

A discussion on how to solve linear and nonlinear inequalities is presented. Both the Test Method and the Factor Method of checking positive/negative intervals are included as part of the discussion.

This resource explains concepts related to set notation and gives examples for each.

A concise presentation of a lesson showing how the Distance Formula is really just the Pythagorean Theorem, and how it can be used to find the distance between two sets of coordinates.

This resource contains a lesson on the slope and y-intercept of a line and how to interpret them in word problems.

Provides a lesson on solving literal equations, explains how they are similar to solving linear equations, and works through numerous examples showing how different types of literal equations are solved.

Describes and gives good examples relating to the slopes of parallel and perpendicular lines.

Demonstrates step-by-step how to complete the square for ellipses and hyperbolas. Includes several charts and graphs for understanding.

Explains the concept of inverse functions, covers some typical exercises, and demonstrates how to find the inverse of a given function.

Demonstrates step-by-step how to complete the square to find the vertex of a parabola. Thorough descriptions of each problem.

Demonstrates step-by-step, with illustrations, how to solve linear equations. Also explains the formatting and reasoning for 'no solution' and 'all x' equations. Includes interactive tool for practice solving linear equations.

Provides a thorough lesson on radical equations. Explains what radical equations are and provides many different examples on how to solve different types of radical equations.

A lesson on graphing radical equations gives numerous example problems which are worked through step by step.