If a parabola's focus is at (−2, 5) and the directrix is at y = −1, what is the equation representing this parabola?
x2 + 4x − 12y + 67 = 0
x2 − 28 = 0
x2 − 4x + 12y − 28 = 0
x2 + 4x − 12y + 28 = 0

Question

If a parabola's focus is at (−2, 5) and the directrix is at y = −1, what is the equation representing this parabola?
 x2 + 4x − 12y + 67 = 0 
x2 − 28 = 0
 x2 − 4x + 12y − 28 = 0
 x2 + 4x − 12y + 28 = 0

kiiraa_x3 · Answer

@Michele_Laino @pooja195 @Hero @triciaal

anonymous · Answer

you can use the definition of a parabola

anonymous · Answer

distance ( -2,5) ( x,y) =  distance ( ( x,y)  , ( x, -1) )

anonymous · Answer

|dw:1447114934973:dw|

anonymous · Answer

y = 1/12 ( (x+2)^2 + 24)
12y = (x+2)^2 + 24 
12y = x^2 + 4x + 4 + 24 
x^2 + 4x - 12y +28= 0

anonymous · Answer

ded. no response