Pre-Calculus & Trigonometry Resources

General

Desmos(dynamic online graphing tool with a free app for Android and iOS!)
Khan Academy (practice exercises and videos)
Kuta Software (worksheets with answer keys)

Quadratic Functions (see Algebra 2 Resources)
Exponential Functions(see Algebra 2 Resources)

Trigonometry
Pi Fight (determine angle measure on the unit circle in radians and degrees)
Trigonometric Graphing (explore the amplitude, period, and phase shift by examining the graphs of various trigonometric functions)

Conic Sections
Conic Flyer (explore graphs with sliders)
Geogebra Applets(2D and 3D GeoGebra applets for studying the conics)