The standard equation of a hyperbola with centre at the origin and foc…

Question

The standard equation of a hyperbola with centre at the origin and foci on the $x$-axis is:

Accepted Answer

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

A hyperbola with foci on the $x$-axis has the standard form $\dfrac{x^2}{a^2} - \dfrac{y^2}{b^2} = 1$ — note the **minus** between the two terms (an ellipse uses a plus).
For foci on the $y$-axis the form flips: $\dfrac{y^2}{a^2} - \dfrac{x^2}{b^2} = 1$.

Answer

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

Answer

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

Answer

$y^2 - x^2 = 4a^2$