## At A Glance

### Pre-Calculus: Fundamental Trigonometric Identities

http://www.mindbites.com/lesson/1217 for full video. http://www.mindbites.com/series/290-trigonometry-basic-trigonometric-identities for a bundle of videos on . For an even broader bundle of videos that cover and , check out http://www.mindbites.com/series/289-trigonometry-trigonometric-identities . To search for topic-specific help in our library of 400+ video products for Trigonometry & Pre-Calculus, please refer to our Trigonometry category at: http://www.mindbites.com/category/31-trigonometry and our Calculus Category at http://www.mindbites.com/category/23-calculus . To check out our full Trig & Pre-Cal video course, with 150 videos included, refer to: http://www.mindbites.com/series/845-trigonometry-full-course . In this lesson, Professor Burger will reveal and explain several basic trigonometric identity proofs. He will begin by reviewing the definitions of sine, cosine, and tangent. From these definititions, he will prove tanx = sinx/cosx. Then, he uses the Pythagorean Theorem to show you the proofs for 3 more trigonometric identities: cos^2 + sin^2 = 1, 1+ tan^2 = sec^2, and 1 + cot^2 = csc^2. Finally, Professor Burger will tell you which of these identities and proofs you need to memorize and which you can derive simply and don't need to fret about memorizing in advance of your test. Taught by Professor Edward Burger, this lesson was selected from a broader, comprehensive course, Precalculus.
Length: 03:16

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