Question

The cartesian co-ordinates of the point on the parabola y² = –16x, whose parameter is `1/2`, are ______.

Options

• (–2, 4)

• (4, –1)

• (–1, –4)

• (–1, 4)

Answer 1

The cartesian co-ordinates of the point on the parabola y² = –16x, whose parameter is `1/2`, are (–1, 4).

Explanation:

∵ y² = –16x

Comparing it with y² = – 4ax

∴ a = 4

Parametric equations are

x = –at², y = 2at

or x = `-4(1/2)^2`, y = `2(4)(1/2)`

or x = – 1, y = 4