পরাবৃত্তের সমীকরণ হল-

$x^{2}+y^{2}=a^{2}$

$y^{2}=4 a x$

$\frac{x^{2}}{a^{2}}+\frac{y^{2}}{b^{2}}=1$

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

$x^{2}-y^{2}=a^{2}$