The equation of directrix of the parabola y2 + 4y + 4x + 2 =... | MATH - PARABOLA | SolveeIt | Solveeit

Today, August 18

Question

The equation of directrix of the parabola y² + 4y + 4x + 2 = 0 is

A

x = –1

B

x = 1

C

x = – $\frac{3}{2}$

D

x = $\frac{3}{2}$

Answer

x = $\frac{3}{2}$

Explanation

Solution

The given equation can be written as

(y +2)² = –4 $\left( x - \frac{1}{2} \right)$

y² = 4AX

̃ A = –1. The directrix is X = –A

̃ $\left( x - \frac{1}{2} \right)$ = – (–1) ̃ x = 3/2