Question

I have a question that is asking me to pick a graph that would best help me find the solution to an equation. Can you please explain this to me? I'll put put the equation if it would help.. @mathmale @BTaylor

Answer 1

*put up

Answer 2

\[\frac{ 2 }{ x } - \frac{ 5 }{ x^2 } = -4\]

Answer 3

I would separate this into two equations: \[y=\frac{2}{x}\] and \[y=\frac{5}{x^2}-4\]
Graph those, then the intersection point is the solution.

Answer 4

Nicole, great to hear from y ou. But I'm in the midst of helping someone else with a lengthy problem. I have plenty of faith in BTaylor and am confident that he can help you further.

Answer 5

I don't think I'm to find the solution of the equation it's but if thats what I have to find the graph then I'll be right on that.

Okay MM, talk to you later!

Answer 6

* itself

Answer 7

If you have a graph with both of those equations shown, then that is the one to pick.

Answer 8

Okay, one moment while I work it out.

Answer 9

I did the first one with the simple -2 through 2 as x to find the points of y but non of them match..

Answer 10

It's not going to be an integer. What form is the answer supposed to be in?

Answer 11

A graph

Answer 12

That you draw or choose?

Answer 13

I did the fill in for x, to find y, to then graph those points

Answer 14

Choose

Answer 15

hmmm...so you want one with a horizontal asymptote at 0 and one with it at -4; both vertical asymptotes will be 0

Answer 16

Um, a bit confused but if what you are saying is what I think you are then I don't have one like that.. All the graphs pass through those points.. I may not be getting this right though

Answer 17

Do you have a pic of the graphs?

Answer 18

Yes, one second..

Answer 19

Nicole: I'd suggest we stop for a moment and review what the goal of this problem is. BT was correct in suggesting that you draw both graphs on ONE set of axes; you then look for the point of intersection. Why?

Answer 20

OK, this is taking a different approach than what I suggested. Now, I'd look plug in y=0 and solve for x. That will give you your x-intercepts, from which you can choose the graph. Sorry for my previously misleading instructions.

Answer 21

Well i started to do the y=2/x but when I saw that non of them matched I stopped.. Do you want me to look at the other one?

Answer 22

no, with the original equation.

Answer 23

Oh, okay. Um, can you give me an explain of the y=0 and solving for x?

Answer 24

again, slight change in plans.
You are given \[\frac{2}{x}-\frac{5}{x^2}=-4\]You want to find the x-value that will give -4.

Answer 25

So you solve for x. From that, look at that x-value(s) on the graphs you have. Where they intersect y=-4 are your solutions. If all the x-values match, that graph is your solution.

Answer 26

Okay, can you still give me an explain? Maybe with a different problem so I can still do this one on my own?

Answer 27

Sorry, I gotta go now. @mathmale can you step in please?

Answer 28

Okay, thank you! @BTaylor

Answer 29

BT: Yes. Thanks very much!

Answer 30

So we meet again (:

Answer 31

Nicole, I'm going to help you. Before we resume work, please tell me, in your own words, what you think the end goal of this math problem is.

Answer 32

I think it is to find a graph that could possible tell you information about the equation with out you having to do any work but I may be wrong..

Answer 33

So you're given an equation and are asked to solve it graphically, not analytically. BT's approach was a good one. He suggested that the solution would be the point at which the 2 different graphs he mentioned intersected.

Answer 34

But non of my graphs intersect..

Answer 35

Shoot. If you're not in a hurry, would you agree to resume this conversation tomorrow? I've been on OpenStudy for hours and am no longer thinking very clearly.

Right: none intersect, BUT (I assume) all but one of them would not be helpful to you in finding a solution.

Answer 36

What's your schedule like?

Answer 37

I'm trying to get as much of my work done as I can before I fall asleep but I can skip this one and come back to it tomorrow if need be.

Answer 38

That'd be better for me. When I can no longer concentrate, this math is no longer fun!

Answer 39

Ha okay. Well hopefully I'll caught you tomorrow! Goodnight MM.

Answer 40

Good morning, Nicole!
What a difference eight hours of rest makes!

This homework problem poses a challenge in that we're to chose which of four graphs best represents the given function\[\frac{ 2 }{ x }-\frac{ 5 }{ x^2 }=-4\]

None of the four graphs represent all three terms of this equation.

However, if we stop to think about it, we can tell that the graphs do not show 2/x, but only 5/x^2 or a combination of that with -4. How do we know that? Because both halves of 1/(x^2) points either upward or downward, whereas the left half of 1/x points downward and the right half points upward. See my drawing, below: