trigonometry question Watch

MEPS1996
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show that sin(theta)/(1+cos(theta))=tan(1/2theta)
any ideas?
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MEPS1996
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the reason i ask this question is because i know its easy just to sub in double angle formulas for the sintheta and costheta, but this question was in an M2 textbook, knowledge of the double angle formula is not a prerequisite a dont think. So anybody see any easy ways without double angle formulas?
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TenOfThem
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(Original post by MEPS1996)
knowledge of the double angle formula is not a prerequisite a dont think
What board do you do - Edexcel states C3 as a pre-requisite for M2

There is no alternative method
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Tom777
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(Original post by TenOfThem)
What board do you do - Edexcel states C3 as a pre-requisite for M2

There is no alternative method
I sit AQA and C4 was required for M2. Even if there was a C2 solution, they wouldn't mark you down for using 'higher level' knowledge.
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GingerCodeMan
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(Original post by MEPS1996)
the reason i ask this question is because i know its easy just to sub in double angle formulas for the sintheta and costheta, but this question was in an M2 textbook, knowledge of the double angle formula is not a prerequisite a dont think. So anybody see any easy ways without double angle formulas?
I sit CCEA, and there have been questions in the past that required knowledge which wasn't on the specification for a particular module. The compound angle formulae are given to us in a formula booklet, and I think that's how you are supposed to find the solution.

Are you able to solve it using the double angle formulae, or would you like an explanation for it?
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ztibor
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(Original post by MEPS1996)
show that sin(theta)/(1+cos(theta))=tan(1/2theta)
any ideas?
Use the double angle formulas at the LHS, then simplify
e,g
\sin \theta =\sin 2\cdot \frac{\theta}{2}=2\cdot \sin \frac{\theta}{2} \cdot \cos \frac{\theta}{2}
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Mr M
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(Original post by TenOfThem)
There is no alternative method
The half tangent formulas are included in the OCR formula book. They could simply be stated.
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