Curated OER
Double-Angle and Half-Angle Formulas
In this college level Pre-Calculus worksheet, students use the double-angle and half-angle formulas to evaluate trigonometric expressions and solve trigonometric equations. The six page worksheet contains fifty-six problems. Answers are...
Massachusetts Institute of Technology
Mit: Useful Trigonometric Identities
This list of trigonometric identities includes the factoring formulas near the bottom. A great tool for reference.
Varsity Tutors
Varsity Tutors: Hotmath: Practice Problems: Double and Half Angle Formulas
Twenty-two problems present a variety of practice working with double-angle and half-angle formulas. They are given with each step to the solution cleverly revealed one at a time. You can work each step of the problem then click the...
Wolfram Research
Wolfram Math World: Hyperbolic Functions
This site from MathWorld explains the hyperbolic function. The information is not too in-depth, but factual and quite a few links are provided for additional information on related subjects.
Wolfram Research
Wolfram Math World: Half Angle Formulas
This page, from Eric Weisstein's comprehensive Math World site, offers information on half-angle formulas. The site includes traditional trigonometric fuctions half-angle formulas as well as hyperbolic half-angle formulas. Includes links...
Math Medics
S.o.s. Math: Double Angle and Half Angle Formulas
Double angles and half angles are explained through step by step examples. The steps are clear and easy to follow.
Math Medics
S.o.s. Math: Table of Trigonometric Identities
This tutorial highlights the numerous trigonometric identites (but does not define the basic trigonometric functions).
CK-12 Foundation
Ck 12: Trigonometry: Half Angle Formulas
[Free Registration/Login may be required to access all resource tools.] Using identities to derive more half angle formulas.
Free Math Help
Free Math Help: Double and Half Angle Formulas
Students learn about the double and half angle formulas. Definitions and formulas are included.