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4 answers

let 1/2 x = t

RHS = (1 - cos 2t)/ sin 2t = (1-(1- 2sin ^2t))/sin 2t

= 2 sin ^2 t/ 2 sin t cos t = sin t/cos t = tan t = tan 1/2 x = LHS

2007-03-10 00:01:36 · answer #1 · answered by Mein Hoon Na 7 · 0 0

Use the fact that sin X/2 = ±√[(1-cosX/2] and cos X/2 = ±√[(1+cosX)/2]. tan X/2 = (sin X/2)/(cos X/2)

2007-03-10 00:27:13 · answer #2 · answered by forgetfulpcspice 3 · 0 0

Let X / 2 = A
RHS
= (1 - cos 2A) / sin 2A
= [ 1 - (1 - 2 sin ² A) ] / 2 sin A.cos A
= 2 sin ² A / 2 sin A.cos A
= sin A / cos A
= tan A
= tan.(X / 2) = LHS

2007-03-10 00:29:30 · answer #3 · answered by Como 7 · 0 0

Let t = tanx/2
Then cosx = 2t/(t^2 +1) and sinx = (t^2 -1)/(t^2 + 1)


etc you'll obtain an equation in the variable t and solve it for t.

2007-03-10 00:01:44 · answer #4 · answered by physicist 4 · 0 0

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