The value of the directrix is -5/4.
According to the statement
we have given that the equation of parabola is y2 = 5x. And we have to find that the which equation represents the directrix.
We know that the general equation of parabola is
(y - k)2 = 4a(x - h) -(1)
and given parabola equation is
y2 = 5x. -(2)
After comparing the both equations we get k=0 and h=0
And the formula to find the directrix is
x = h - a
Substitute the values of h and a in it then
x = 0-5/4
x = -5/4.
Here the directrix is -5/4.
So, The value of the directrix is -5/4.
Learn more about the Parabola here brainly.com/question/4061870
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