The vertex of the parabola is between the shortest line connecting its focus and directrix, so between (0, -4) and y = 4 is the point (0, 0), which is the vertex of the parabola. Also, this parabola faces downward.
The general formula for a parabola that faces downward is y = -4cx^2, where c is the distance from the vertex to either to focus or the parabola. Since c = 4, the equation is y = -16x^2, which is choice A.
I think the answer is y=3
Answer:
18x^2+6
Step-by-step explanation:
2(9x^2+3)
multiply each term in parentheses by 2
2 x 9x^2+2 x 3
calculate product
18x^2+2 x 3
multiply numbers
18x^2+6
42. This is because you cross out the numbers left from right until theres a number inbetween.