Question

write the equation of the parabola with focus (1, -3) and vertex (5, -3)??

Answer 1

it opens to the left

Answer 2

the a value = 4

y^2 =16x modify for off centered

Answer 3

alright thanks, but how did you know that

Answer 4

opps; opens left

Answer 5

the line between the vertex and foci is straight along the y = -3 axis

Answer 6

the vertex is the bend and the focus is inside the curve

Answer 7

the distance from the vertex to the focus is the "a" value in the parabola formula from geometery

Answer 8

y^2 = -4ax

Answer 9

is that the directrix?

Answer 10

the directix is on the other side of the vertex; the distance 'a'

Answer 11

the directix would be at x=9

Answer 12

ok

Answer 13

thank you

Answer 14

youre welcome :)

the complete answer is:

(y+3)^2 = -16(x-5)

Answer 15

lol thanks again :)

Answer 16

do you know what the latus rectum of a ellipse is?

Answer 17

sounds painful; .... i prolly do, but just dont know the proper term for it :)

Answer 18

haha i was out of school and i come back i was like wtf???

Answer 19

it is defined as the chord running thru the focus

Answer 20

mhmm

Answer 21

amistre64 come back to mine please

Answer 22

(y+3)^2 = -16(x-5) plug in x = 1

-16(-4) =

y^2 + 9 + 6y = -64

y^2 +6x +73 = 0

Answer 23

6x shoulda been 6y

Answer 24

the latus rectum is the line thru the foci and those y values

Answer 25

but thats a parabola right? the ellipse's equation is (x-3)^2/16 + (y+6)^2/4 = 1

Answer 26

i forgot how to multiply lol

Answer 27

http://www.google.com/search?q=latus+rectum+ellipse&oe=utf-8&rls=org.mozilla:en-US:official&client=firefox-a&um=1&ie=UTF-8&tbm=isch&source=og&sa=N&hl=en&tab=wi&biw=1024&bih=622

Answer 28

same concept; its the line thru the focus that runs perp to the center line

Answer 29

oh ok
well, thank you

Answer 30

we got about a min b4 they shut the site down for maintainence

Answer 31

dang