Question

Which conic section does the equation below describe (y-1)^2=8(x+3) circle, ellipse, parabola, hyperbola

Answer 1

work it all out and put it in a standard form, of x^2 +- y^2 = 1

Answer 2

would it be y^2+1=8x+24?

Answer 3

@DanJS

Answer 4

hi

Answer 5

is this right y^2+1=8x+24

Answer 6

Parabola with a horizontal axis.
Vertex at (h,k)
Focus is (h + p, k).
Directrix is the line
x = h – p.
Axis is the line y = k.

(y – k)^2 = 4p(x – h) and \[p \neq 0\]

Answer 7

reload page

Answer 8

how did you know that it was a parabola? I have 4 more questions like that and i would like to be able to know how to do them

Answer 9

a basic parabola takes the form y = x^2

Answer 10

or x = y^2

Answer 11

for (x-1)^2/20-(y+2)^2/16=1
would it be a ellipse

Answer 12

here is a good link that will help you identify conic sections. Put the equation they give you into a standard form.
http://hotmath.com/hotmath_help/topics/conic-sections-and-standard-forms-of-equations.html

Answer 13

no, an ellipse is x^2/a + y^2/b = 1

a Hyperbola has a minus sign instead of a plus

Answer 14

remember a circle is x^2 + y^2 = 1

an ellipse is just another less perfect kind of circle, that is what the 'a' and 'b' come in.

Answer 15

so the answer to that problem would be a hyperbola?

Answer 16

yes, if it was a plus then it would be a ellipse

Answer 17

(x+2)^2/16+(y-9)^2/36 is an ellipse, right?

Answer 18

what do you think?

Answer 19

yes because it has a +

Answer 20

yep, look at the third entry on the table in that link

Answer 21

(h,k) =( -2,9)

Answer 22

(x+2)^2=4(y-3) is a circle
and 2x^2+2y^2-6x+4y+1=0 is a parabola

Answer 23

Whatever is in the parenthesis like (x-4)^2 is a translation of the center of the ellipse, and the divisor is what stretches the thing out

Answer 24

ok the first one is not a circle

Answer 25

a circle would contain, squares on both the x and the y terms

Answer 26

circle: x^2 + y^2 = 1
center at the origin and radius 1

Answer 27

ugh. this is so confusing... the first one would be a parabola

Answer 28

yes, it is just like the first question you asked with different numbers.

Answer 29

but the first question you said it was a circle

Answer 30

no, the original question you asked is a parbola.

Answer 31

If you only have to choose between parabola, hyperbola, and ellipse/circle

just remember, a parabola only has one of the terms squared
an ellipse/circle has both positive x^2 and y^2
a hyperbola has one subtracted, a minus x^2 or y^2 term

Answer 32

For that one, Have you done "completing the square" in class?
2x^2+2y^2-6x+4y+1=0

Answer 33

1) (y-1)^2=8(x+3) parabola
2) (x-1)^2/20 - (y+2)^2/16=1 hyperbola
3) (x+2)^2/16 + (y-9)^2/36=1 ellipse
4) (x+2)^2=4(y-3) parabola
5) 2x^2+2y^2-6x+4y+1=0 circle
are these answers correct?

Answer 34

yes

Answer 35

to put the last one in a more familiar standard form for a circle, you need to "complete the square"

Answer 36

(x-h)^2 + (y-k)^2 = r^2 ---circle centered at (h,k) -- radius = r

Answer 37

sorry my internet went out. this is my first time here on this site.. but I can see that I should like give a medal but i don't know how to do that for you or can I since im new

Answer 38

ha, i dont really know, just been here a couple days myself, maybe just hit best response button

Answer 39

alright well thank you for you help!