Trigonometry Identities I Introduction

Sin 2X = cos cos x 2Cos X 2 2 Sin (90) cos (90) 2 Sin 30- 2 • 1/2 Sin 60 Tan 2X = 2Sin X 2Ta1LX —Tan X 2. sin 30 + sin 60 1/2+ 3/2 3 2. 1/2 sin 90 ... Multiply by TanX (to get lid of the CotX) since 1 + Tan = Sec simplify square both sides and substitute Step 2: Factor and solve. + 2TalLX x SecX 1 + + 4Tan X 1 + + 4Tan X ................
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