Question

Find the equation of the parabola with vertex at the origin, axis along Y-axis and passing through the point (–10, –5).

Answer 1

The axis of the parabola is along Y-axis and vertex is at the origin.

∴ its equation is of the form x² = 4by

But (– 10, – 5) lies on it

∴ (– 10)² = 4b(–5)

∴ 4b = – 20

∴ equation of the required parabola is x² = – 20y.