Originally Posted by

**skabani** Any help would really be appreciated:

Express the distance from point (x,y) on the graph y = 4 - x^2 to the point (0,1) as a function of x. Give the domain of the function.

The distance formula says the distance, $\displaystyle d(x,y)$, between two points $\displaystyle (x_1, y_1)$ and $\displaystyle (x_2,y_2)$ is given by:

$\displaystyle d(x,y) = \sqrt {(x_2 - x_1)^2 + (y_2 - y_1)^2}$

**Hint:**

For the graph $\displaystyle y = 4 - x^2$, any arbitrary point $\displaystyle (x,y)$ on the graph can be represented as $\displaystyle \left( x,4 - x^2 \right)$