Find the equation of the parabola whose focus is (0,-7) and vertex is (0,0) 

Asked by Topperlearning User | 13th Nov, 2016, 05:54: PM

Expert Answer:

The axis is the y - axis, hence the parabola is either an upward or a downward parabola with equations x2 = 4ay or x2 = -4ay respectively. Since focus is a = -7 we use the equation x2 = -4ay.

Hence the equation is x2 = -4 7 y

x2 = -28y.

Alert!  The negative sign signifies the type of parabola. Do not replace a as -7 for the sign is considered in the equation itself.

Answered by  | 13th Nov, 2016, 07:54: PM