Question

can someone please help me learn how to graph quadratic equations? I WILL GIVE A MEDAL!!

Answer 1

you mean like parabolas

Answer 2

Jay - you are familiar with graphs already correct? x values go horizontzlly y values go vertically

Answer 3

yes I am pretty familiar with them, for the most part, yes. @wolf1728

Answer 4

Okay the reason I asked is what help do you need? If you were to plot y = x² + 4x -7
You just calculate the values for x from -10 to 10 and plot the y values for whatever the x values are

Answer 5

okay, so can you help me solve, y=-5x^+1 @wolf1728

Answer 6

That would be y = -5x² +1 right?

Answer 7

yea

Answer 8

So, I would calculate the y values for each x value of -10 to 10
If you have the software from Open Office (100% free) this would allow you to do this very quickly. Do you have Open Office?

Answer 9

probably not

Answer 10

It is WELL WORTH downloading because not only does it calculate values for you, it will also make a graph for you. (pretty useful huh?)

Answer 11

well yes, but I have a final tmrw, and I need to memorize the formula of the problem. it would be very helpful if u show me step-by-step yo.

Answer 12

Here are the figures from -10 to 10
-10 -499
-9 -404
-8 -319
-7 -244
-6 -179
-5 -124
-4 -79
-3 -44
-2 -19
-1 -4
0 1
1 -4
2 -19
3 -44
4 -79
5 -124
6 -179
7 -244
8 -319
9 -404
10 -499

If you were to graph this, it seems choosing the values x =-2 through x=2 would keep the graph reasonably small.
Still I will attach the graph form x = -10 to x=10

Answer 13

okay, thanks wolf..

Answer 14

There is no "formula" to do this, but there are a few things to know.

If the coefficient of x² is positive, graph is shaped like a 'U'
If it is negative graph is shaped like this ∩

Answer 15

The roots of the quadratic equation will cross at the x axis:
roots of this equation are -0.44721 and 0.44721
Redrawing the graph look at where the graph crosses the x axis.

Answer 16

okay..

Answer 17

Another graph