# Thread: Convert rectangular equation to polar equation

1. ## Convert rectangular equation to polar equation

How do I convert the hyperbola equation x^2/100^2 - y^2/75^2 = 1 to the polar form r = ed/1+ecos<theta>? Am I correct that c = 125 and e = c/a = 1.25?

2. Hello, skierr4f3!

How do I convert the hyperbola equation, $\frac{x^2}{100^2} - \frac{y^2}{75^2} \:= \:1$
. . to the polar form: . $r \:= \:\frac{ed}{1 + e \cos\theta}$ ?
It can't be done directly . . .

The rectangular form has its center at the origin.

The polar form has a focus at the pole (origin).

Am I correct that: $c = 125$ and $e \,=\, \tfrac{c}{a} \,=\,1.25$ ?
Right!