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# Trigo proving Tweet

Maths and statistics discussion, revision, exam and homework help.

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1. Trigo proving
Lost touch with trigo since never touched for a while..here's a qn
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2. Re: Trigo proving
1) Look up the trigonometric addition formulae for sine

2) Expand out the brackets - the first term on the left is , for example.

That should be enough
3. Uh,but thats where im stuck at,cannot prove
4. Re: Trigo proving
So you have , but with

Then you can use the formula
5. Re: Trigo proving
Uh,but thats where im stuck at,cannot prove
6. LHS = sin r@ cos 0.5@ - cos r@ sin0.5@

Expanded..,where @ means tether
7. Re: Trigo proving
Lost touch with trigo since never touched for a while..here's a qn
Abbreviate it to trig

trigo is gay...
8. Got it case closed~thx all
Last edited by Vadevalor; 14-07-2012 at 03:17.