I haven't used my algebra skills much for years and they seem to have atrophied significantly!
I'm having real trouble working out how to re-arrange a formula I've come across to get $x$ by itself on the left hand side. It looks like this:
$\frac{x}{\sqrt{A^{2}-x^{2}}}=\frac{B+\sqrt{C+Dx}}{E+\sqrt{F+G\sqrt{A^{2}-x^{2}}}}$
I've tried every method I can remember but I can't get rid of those pesky square roots!
Any ideas?