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Trig Proof

  • Thread starter thomas49th
  • Start date
  • #1
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Prove:

[tex]\frac{Sec^{2}\frac{y}{2}}{2} \eqiv \frac{2}{1+x^{2}}[/tex]

Well i know from the pythagorean identities that tan^{2}x + 1 = sec^{2}x
so

[tex]\frac{tan^{2}\frac{y}{2} + 1}{2} \eqiv \frac{2}{1+x^{2}}[/tex]

But now im stuck!

If your interested the full qusetion is page 35, question 7 (ii) here:

http://www.edexcel.org.uk/VirtualContent/105484/GCE_Pure_Maths_C1_C4_Specimen_Paper_MkScheme.pdf

Can someone point me in the right direction

Cheerz
 

Answers and Replies

  • #2
tiny-tim
Science Advisor
Homework Helper
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The actual question is:

Given that x = tan(y/2), prove that dy/dx = 2/(1 + x²).​

thomas49th, just differentiate both sides of x = tan(y/2). :smile:
 

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