# Half-Circle Function

## Half-Circle Function

Function defined by a relation in the form f(x) = $$\sqrt{{r}^{2} – {x}^{2}}$$ or f(x) = − $$\sqrt{{r}^{2} – {x}^{2}}$$ where r is the radius of a circle centered on the origin point.

### Examples

Here is the graph of the function defined by the relation f(x) = $$\sqrt{{4} – {x}^{2}}$$ :

Here is the graph of the function defined by the relation f(x) = − $$\sqrt{{4} – {x}^{2}}$$ :