Trigonometry Identities II Double Angles

For 1 Cosx 0 1) Sin2x+sinx=0 2SimCosx + sim- factor and solve: Sim- (2Cosx + 1) 0 0 2) cos2x 2Cos x 0 0 and 30-60-90 triangles For Cosx + 1 — 0 cos x = 0 1 + Cos x Cosx For 2Cosx Cosx x 0 and factor and solve: Since U 2Cos x (2Cosx + Cos x 1 2 30, 150, 75, 390, 195, 510 255 www.mathplane.com [0, 360 ) 3) 4Sinecos 2(2Sine cos e 2(sin2 ) Sin2 ................
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