Trigonometry Identities I Introduction

2Cos x - cosx-2 cosX(2Cosx- ) 2Cosx cosx 2Cosx cos x (2Cosx cosx (2Cosx - (2Cosx (2Cosx ) cos x ) x ) X cosx cosx (distributive property to rearrange and regroup) 0 Step 4: Solve and check. 2Cosx - 1 x- 1/2 x = 60, 300 Check X 2 cos x cos x cos x cos x 80 60 2 /2 0 0 0 0 both sides by Cosine) (square root both sides) ................
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