Function defined by a relation in the form

*f*(

*x*) = \(\frac{b}{a}\) \(\sqrt{{a}^{2}~ – {x}^{2}}\) or

*f*(

*x*) = − \(\frac{b}{a}\) \(\sqrt{{a}^{2}~ – {x}^{2}}\) where

*a* is the horizontal half-axis and

*b* is the vertical half-axis of an ellipse centered on the origin point.

### Examples

Here is a graph of a function defined by the *f*(*x*) = \(\dfrac{1}{3}\) \(\sqrt{{9}~ – {x}^{2}}\) :

Here is a graph of the function defined by the relation *f*(*x*) = − \(\dfrac{1}{3}\) \(\sqrt{{9}~ – {x}^{2}}\) :