# Ellipse equation review

Review your knowledge of ellipse equations and their features: center, radii, and foci.

## What is the standard equation of an ellipse?

$\dfrac{(x-h)^2}{a^2}+\dfrac{(y-k)^2}{b^2}=1$
This is the standard equation of the ellipse centered at $(h,k)$, whose horizontal radius is $a$ and vertical radius is $b$.
Which ellipse is represented by the equation $\dfrac{(x-4)^2}{9}+\dfrac{(y+6)^2}{4}=1$ ?