Question

does anybody know anything about graphing a parabola? y=-1/4 x^2

Answer 1

well since it's negative it goes down

Answer 2

i have to plot the vertex and 4 additional points..

Answer 3

since there's nothing subtracted from x, it's centered vertically (symmetrical about the Y axis)

Answer 4

and since it's 1/4 that means it's wider than a "standard" parabola

Answer 5

so the vertex would be center?

Answer 6

yes.

Answer 7

what would i need to do to find the other points?

Answer 8

You can make as many points as you want by picking any value for X, plugging it into the equation, and getting out a value for Y.

Answer 9

Here there is a program where you type in the equation and the graph pops up, its free and I use it all the time. It is called Geogebra, search it on google, you will find it.

Answer 10

So I'd pick "easy" values for X like 1, -1, 2, -2, etc.

Answer 11

so then i would just type any of those in and solve?

Answer 12

right

Answer 13

there are infinitely many points on a parabola, and so if you put *any* value in for X and solve, you'll get the corresponding Y value at that point.

Answer 14

Let me post an example.

Answer 15

This is something I made with geogebra a while ago for someone who had questions about quadratic equations previously.

Answer 16

Here we go:

Answer 17

on that map where would i know what the points are ?

Answer 18

Wolfram alpha is also easy to use for online graphing. Here's what our parabola looks like: http://www.wolframalpha.com/input/?i=-%281%2F4%29x%5E2

Answer 19

You would have to look which go on there perfectly like for example: (4, -4)

Answer 20

so basically its wherever 2 points meet perfectltly

Answer 21

Yup, you try to look for one, and tell me what point you think

Answer 22

kk one minute

Answer 23

(4,-4)

Answer 24

Ok what about another one?

Answer 25

(5,-6)

Answer 26

Correct :)

Answer 27

(2,1)

Answer 28

2,-1

Answer 29

Yup thats another one

Answer 30

actually -2,-1

Answer 31

Well actually both are

Answer 32

the side ways number is always first then verticle right?

Answer 33

yes. the first number is X - horizontal/sideways.
The second number is Y -- vertical/up-and-down

Answer 34

when i do it for my work it looked all crazy hold on going to try and attach the file

Answer 35

Oki doki

Answer 36

it wont let me post it hmnnn

Answer 37

yay got it right guys thank you