Which is the equation of a parabola with Vertex (0,0) and directrix y=4?

a p = -8x

c. x² = -87

b. ² = -16x

d x2 =-16y

Please select the best answer from the choices provided

x² = -16y

Step-by-step explanation:

We are given:

Vertex (0,0)

Directix y = 4

Here we are asked to find the equation of a parabola given the above conditions.

The standard form of a parabola is

x² = 4ay (1)

directix y = -a(2)

In this question, we are given directix y = 4, so lets substitute 4 for y in the equation 2 above.

Thus, we have:

4 = -a

a = -4

Let's now substitute -4 for -a in equation 1.

x² = 4ay

x² = 4 * -4 * y

x² = -16y

Therefore, the equation of a parabola with Vertex (0,0) and directrix y=4 is (x² = -16y)

-13

step-by-step explanation:

f(x)=2x-5 for f(-4)

f(-4)   means let x=-4

f(-4) = 2(-4) -5

f(-4) =-8-5

      = -13

he used the algebra tiles correctly.

step-by-step explanation:

given : 3x(2x-1)

solution :

since he used algebra tiles .

armando's solution is the same in the solution shown in figure

as he distributed 2x into x and x and wrote them vertically

and also write   -1 vertically

and 3x into x and x and x and wrote it horizontally

performing the multiplication in the algebra tiles we get

and solving the given expression :

3x(2x-1)

since solving the expression using tiles   and solving the expression algebraically we get the same answer

thus   we can choose the first statement as the answer to this problem which is "he used the algebra tiles correctly".