Question

What is the equation of the directrix of the parabola with equation x=4y^2+16y+19

Answer 1

first find the vertex by using completing the square

Answer 2

ill just guess on this one thanks anyway

Answer 3

haha ok, don't you want to learn how to do these problems

here i'll show you the steps:
i'll use the shortcut way of getting vertex --> y = -b/2a = -16/8 = -2
plug that in to get x_coordinate
x = 4(-2)^2 +16(-2) +19 = 3

vertex: (3,-2)

directrix: x = h-p
where p = 1/(4a) = 1/16
h = 3

--> x = 3- 1/16
--> x = 48/16 - 1/16
--> x = 47/16

Answer 4

I just put x=-2 1/16

Answer 5

?

Answer 6

for the answer. It is multiply choice so that is what i chose

Answer 7

yeah you guessed...but i showed you the solution, can you follow my steps?

Answer 8

i cant learn over typing. I have to hear someone walk me through it. I have memory loss too so i wont be able to remember it anyway

Answer 9

oh ok so you probably should go somewhere else for help then
anyway answer is x=47/16 or x=2 15/16

Answer 10

i know i should but thank you for helping