# Math Help - Conics, Rectangular Hyperbola

1. ## Conics, Rectangular Hyperbola

Hey guys
how do I prove that the angle between the asymptotes of a rectangular hyperbola is 90 degrees

I derived the formula from a previous step in the question to find the angle between $\frac{x^{2}}{a^{2}}-\frac{y^{2}}{b^{2}}=1$ which was $\theta=\tan^{-1} (\frac{2ab}{a^{2}-b^{2}})$

so now that in a rectangular hyperbola $x^{2}-y^{2}=a^{2}$..and now that $a^2 =b^2$, how do i prove that the angle is $90^\circ$

Thanks

2. Originally Posted by aonin
how do I prove that the angle between the asymptotes of a rectangular hyperbola is 90 degrees

One way: the asymptotes of

$\dfrac{x^2}{a^2}-\dfrac{y^2}{a^2}=1$

are:

$y=\pm \;x$

Fernando Revilla