# How can I tell whether an ellipse is a circle from its general equation?

##### 1 Answer

Jul 16, 2015

#### Answer:

A circle in general form has the same non-zero coefficients for the

#### Explanation:

Don't be too hasty, though.

Assuming that there is ineed a graph, it is:

an ellipse if

a circle if

However it is possible that there is no graph: