Derive the equation of the parabola with a focus at (-2, 4) and a directrix of y = 6. Put the equation in standard form.

Question

campbell_st · Answer

well the parabola is concave down because the directrix is above the focus. 

half the distance between the focus and directrix is called the focal length a and in this question it is negative. 

the vertex lies halfway between y = 4 and y = 6

the x value of the vertex is the same as the  focus

so the general form is 

$$y = a(x -h)^2 + k$$

where (h, k) is the vertex. 

hope this helps

anonymous · Answer

do you know what the answer is perhaps? lol

lukecrayonz · Answer

Is this FLVS?