# rearranging formula q

• May 2nd 2011, 11:50 AM
jharrisbr8
rearranging formula q
Hi everybody, can somebody tell me were I'm going wrong, this is driving me mad

Make p the subject

http://latex.codecogs.com/png.latex?...B%202%7D%20%7D =1

I get

http://latex.codecogs.com/png.latex?...B2%20%7D%7D%7D =p

Which apparently is incorrect. I'd love to show you the steps I took, but this is my first ever post and I'm really struggling with the latex workaround.(Worried)
• May 2nd 2011, 12:01 PM
SpringFan25
Im wont try and diagnose your mistake without seeing your working. My attempt:

http://quicklatex.com/cache3/ql_7147...c44344a_l3.png
• May 2nd 2011, 12:54 PM
jharrisbr8
Hmmm, I get what you've done, but the answer the book gives is

http://latex.codecogs.com/png.latex?...B2%20%7D%7D%7D

(Worried)
• May 2nd 2011, 01:32 PM
TheEmptySet
Quote:

Originally Posted by jharrisbr8
Hmmm, I get what you've done, but the answer the book gives is

http://latex.codecogs.com/png.latex?...B2%20%7D%7D%7D

(Worried)

The answers are equivalent if

$q > 0$

$p=\frac{x}{\sqrt{1-\frac{y^2}{q^2}}}=\frac{x}{\sqrt{\frac{q^2-y^2}{q^2}}} =\frac{x}{\frac{\sqrt{q^2-y^2}}{|q|}}=\frac{|q|x}{\sqrt{q^2-y^2}}$
• May 2nd 2011, 01:47 PM
jharrisbr8
Got it!

What a relief, thanks Guys.