## anonymous one year ago Derive the equation of the parabola with a focus at (−5, 5) and a directrix of y = −1

1. anonymous

@Michele_Laino @taramgrant0543664 @UsukiDoll

2. exoticinspirit

first What is the equation for a parabola

3. anonymous

no idea

4. anonymous

To find a quadratic equation from a parabola using distances, use the combined distance formula. $\sqrt{(y_2-y_1)^2+(x_2-x_1)^2}=\sqrt{(y_2-y_1)^2}$ Plug in the focus on the left side of the equation. Plug in the directrix on the right side.

5. triciaal

|dw:1439011663445:dw|

6. triciaal

the focus is the point central to all points on the parabola. the directrix is perpendicular to the line from the focus to the vertex through the point same distance as focus to the vertex