What is the equation of the parabola with a focus at (3,6) and a directrix of y= 0?
The vertex form of the equation for the parabola is:
The directrix is a horizontal line, therefore, the vertex form of the equation of the parabola is:
The x coordinate of the vertex, h, is the same as the x coordinate of the focus:
The y coordinate of the vertex, k, is midpoint between the directrix and the focus:
The signed vertical distance, f, from the vertex to the focus is, also, 3:
Find the value of "a" using the formula:
Substitute the values of h, k, and a into equation :