Question

The equation of the directrix of parabola $5 y ^ { 2 } = 4 x$ is

• A. $4 x - 1 = 0$
• B. $4 x + 1 = 0$
• C. $5 x + 1 = 0$
• D. $5 x - 1 = 0$

Answer 1

Answer: (C)

$5 x + 1 = 0$

Answer 2

The given parabola is $y ^ { 2 } = \frac { 4 } { 5 } x$ . Here $a = \frac { 1 } { 5 }$ .

Directrix is $5 x + 1 = 0$