Solveeit Logo

Question

Question: The locus of the point of intersection of the tangents to the parabola x<sup>2</sup> – 4x – 8y + 28 ...

The locus of the point of intersection of the tangents to the parabola x2 – 4x – 8y + 28 = 0 which are at right angles is

A

y = 0

B

y = –1

C

x = 1

D

y = 1

Answer

y = 1

Explanation

Solution

Locus of point of intersection of ^ tangent

(i) Directrix

x2 – 4x – 8y + 28 = 0

Ž x2 – 4x = 8y – 28

Ž x2 – 4x + 4 = 8y – 28 + 4

(x – 2)2 = 8(y – 3)

Ž X2 = 8Y

Directrix

Y = – 2

Ž y – 3 = – 2

y = 1