Question

NEED HELP! Find the vertex, focus, directrix, and focal width of the parabola.

negative 1 divided by 16 times x squared = y

Vertex: (0, 0); Focus: (0, -4); Directrix: y = 4; Focal width: 16
Vertex: (0, 0); Focus: (-8, 0); Directrix: x = 4; Focal width: 64
Vertex: (0, 0); Focus: (0, 4); Directrix: y = -4; Focal width: 4
Vertex: (0, 0); Focus: (0, -4); Directrix: y = 4; Focal width: 64

Answer 1

HI!!

Answer 2

it would be easier if you wrote it as \(-16y=x^2\)

Answer 3

then it looks more like
\[4py=x^2\]

Answer 4

Ah, sorry

Answer 5

yeah i know, but if you multiply both sides by \(-16\) you get
\[-16y=x^2\] really we have no work to do here, because the focal width is \(|-16|=16\) and you only have one choice with that answer

Answer 6

THANKS!
@misty1212 would u mind looking at this one please?
Determine if the graph is symmetric about the x-axis, the y-axis, or the origin.

r = -3 + 3 sin θ

y-axis only
Origin only
x-axis only
No symmetry