Question

A parabola with a vertex at (0,0) has a directrix that crosses the negative part of the y-axis. Which could be the equation of the parabola? x2 = –4y x2 = 4y y2 = 4x y2 = –4x

Answer 1

Given:

vertex of the parabola = (0,0)

The directrix of the parabola crosses the negative part of the y axis .

To Find :

What could be the equation of this parabola ?

Solution :

The graph of the parabola is shown in the attached fig .

Now , since the vertex of the parabola is origin i.e. (0,0) , so its equation should be of the form :

$(x-0)^2 =4.a.(y-0)$

Or, $x^2 = 4ay$

Here from the given options in the question we can see that in all the options a = 1 .

So , the equation of this parabola with a=1 is $x^2 = 4y$ .

Hence the equation of this parabola could be $x^2 = 4y$

Answer 2

Answer:

x^2 = 4y

Step-by-step explanation: