PreCalculus - Trigonometry: Trig Identities (21 of 57) Proof Using Addition & Subtraction Formulas

4,853 views · Published 14 August 2014 · 3:55 · Indexed 12 November 2026

Channel: Michel van Biezen · 2014 · Education

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In this video I will prove the trigonometric identity [sin(A+B)-sin(A-B)]/[cos(A+B)+cos(A-B)]=tanB.

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