Write an equation for the parabola with focus at (0, -2) and directrix x = 2.
Solution:
Given,
Focus at (0, -2), directrix x = 2.
Parabola, open curve, a conic section produced by the intersection of a right circular cone and a plane parallel to an element of the cone.
As a plane curve, it may be defined as the path (locus) of a point moving so that its distance from a fixedline(the directrix) is equal to its distance from a fixed point (the focus).
The equation of the parabola with focus and directrix - F(a, b), D(y = c) is given by
(x - a)2 + b2 - c2 = 2y(b - c)
Substitute F(0, -2) and D(x, 2) ∀ x:y(x) = c
x2 - 2y(2 - (-2) ) = -8y
y = -1/8x2.
Therefore, the equation for the parabola is y = -1/8x2.
Write an equation for the parabola with focus at (0, -2) and directrix x = 2.
Summary:
Equation for the parabola with focus at (0, -2) and directrix x = 2 is y = -1/8x2.
Math worksheets and
visual curriculum
visual curriculum