Question

Which equation represents the directrix? y = –20 x = –20 y = Negative five-fourths x = Negative five-fourths.

Answer 1

The value of x will be given as    $X=\dfrac{-5}{4}$

What will be the value of X?

Here it is given that

The equation of the parabola is

$y^2=5x$

We know that the general form of the parabola is

$(y-k)^2=4p(x-h)$

Also  $x=h-p$

here we have

$y^2=5x$

$(y-0)^2=5(x-0)$

$(y-0)^2=\dfrac{4}{4} \times 5(x-0)$

$(y-0)^2=4\times \dfrac{5}{4} (x-0)$

Now comparing it with  $(y-k)^2=4p(x-h)$

$p=\dfrac{5}{4}$

$k=0\\h=0$

Now

$x=h-p$

$x=0-\dfrac{5}{4}$

$x=-\dfrac{5}{4}$

Thus the value of x will be given as    $X=\dfrac{-5}{4}$

To know more about parabola follow

https://brainly.com/question/4148030

Answer 2

Answer:

D

Step-by-step explanation: