A lesson plan where students will interpret the trigonometric functions in terms of the unit circle, graph a sinusoidal function, and use a sinusoidal function to make interpretations in a modeling context.

Given the sine (or cosine) of an angle, find its cosine (or sine) using the Pythagorean identity. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.

Here is a site that clearly and thoroughly explains the trigonometry of a right triangle, including finding the values of all six trig functions given a single value. There are example problems solved, problems for the student to...

An introduction to solving acute and obtuse triangles by using the law of cosines, including a derivation of the formula. Includes several pistures and examples.

[Free Registration/Login may be required to access all resource tools.] Finding the value for trigonometric functions for angles exceeding 360 degrees.

[Free Registration/Login may be required to access all resource tools.] Learn how to define trigonometric functions of angles with negative values.

[Free Registration/Login may be required to access all resource tools.] Determine if three side lengths make a right triangle, and given the length of its legs, find the length of a right triangle's hypotenuse.

[Free Registration/Login may be required to access all resource tools.] Find all angles on the unit circle matching exact trig ratios. Resource includes examples, videos, and practice problems.

An introduction to viewing the complex plane in terms of polar coordinates. Assumes knowledge of the conversion formulas. Includes several examples and pictures.

An introduction to DeMoivre's Theorem for quickly finding the powers of complex numbers. Assumes knowledge of polar form of complex numbers. Includes several examples and pictures.

The practice problem uses a straightedge and a figure to approximate the solution of each equation. The figure is available in PDF format.

The practice problem uses a straightedge and a figure to approximate the solution of each equation. The figure is available in PDF format.