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#1
Mar 27 2014 03:17am
I don't know how to do this fraction. I am doing rational functions.

I am trying to plot the an equation and one of the numbers is x=1/2

7(x)/x^2-4

__7x__
x^2 - 4

So how do I do 1/4 - 4? I get the 7/2 part but not the 1/4 - 4 crap. Then it's 7/2 over 1/4 - 4. :wacko:

The answer is -14/15 but I do not know how they got that.

This post was edited by NinjaSushi2 on Mar 27 2014 03:38am
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#2
Mar 27 2014 03:40am
Quote (NinjaSushi2 @ 27 Mar 2014 09:17)
I don't know how to do this fraction. I am doing rational functions.
I am trying to plot the an equation and one of the numbers is x=1/2
7(x)/x^2-4
__7x__
x^2 - 4
So how do I do 1/4 - 4? I get the 7/2 part but not the 1/4 - 4 crap. Then it's 7/2 over 1/4 - 4.  :wacko:


when is 1/2, x^2 is 1/4 so what you get is (7/2)*1/(-3.75) so it's -0.93333333...
the problems are x=+2 and x=-2 then your denominator is 0

the numerator is always negative for x negative and positive for x positive
the denominator is positive for (-inf,-2) U (+2,+inf) and negative for (-2,+2)
for large numbers the function is ~7/x which means it goes close to zero the larger x gets, so

when you plot the function from the left (-infinity) it will start from being (close to) zero and drop towards -infinity when you get close to -2
at -2 it will switch to +infinity, pass through 0 at x=0 and drop to -infinity when you reach +2
then it will switch to +infinity and drop towards zero when x goes towards +infinity

hope that clears it up

This post was edited by brmv on Mar 27 2014 03:43am
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#3
Mar 27 2014 03:45am
Quote (brmv @ 27 Mar 2014 04:40)
when is 1/2, x^2 is 1/4 so what you get is (7/2)*1/(-3.75) so it's -0.93333333...
the problems are x=+2 and x=-2 then your denominator is 0

the numerator is always negative for x negative and positive for x positive
the denominator is positive for (-inf,-2) U (+2,+inf) and negative for (-2,_2)
for large numbers the the function is ~7/x which means it goes close to zero the larger x gets, so

when you plot the function from the left (-infinity) it will start from being (close to) zero and drop towards -infinity when you get close to -2
at -2 it will switch to +infinity, pass through 0 at x=0 and drop to -infinity when you reach +2
then it will switch to +infinity and drop towards zero when x goes towards +infinity

hope that clears it up


Thanks for the reply. I can graph it no problem. The problem is my math lab wants me to give the answer to the equation before I graph all of them or it is wrong. I am not sure how to get that answer.



I am not sure why I didn't SS it earlier. :bonk:

This post was edited by NinjaSushi2 on Mar 27 2014 03:45am
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#4
Mar 27 2014 03:53am
Quote (NinjaSushi2 @ 27 Mar 2014 09:45)
Thanks for the reply. I can graph it no problem. The problem is my math lab wants me to give the answer to the equation before I graph all of them or it is wrong. I am not sure how to get that answer.
http://i.imgur.com/63M2rVQ.png
I am not sure why I didn't SS it earlier.  :bonk:


the s/s is not easy to read so you might enlarge it a bit before posting

what answer? not sure what the question is

ps: you don't need to plot on 'paper', you just need to visualise the graph :)

pps: if it is the result -14/15, then read my previous post because -14/15=-0.9333.... (first line)

This post was edited by brmv on Mar 27 2014 04:01am
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#5
Mar 27 2014 04:00am
Quote (brmv @ 27 Mar 2014 04:53)
the s/s is not easy to read so you might enlarge it a bit before posting

what answer? not sure what the question is

ps: you don't need to plot on 'paper', you just need to visualise the graph  :)


The screenshot is easy for me to read. It is 1920x1040 so I am not sure what resolution you are on. (1080 original but imgur reduced it some.)

The very bottom it says -14/15. So how do they get -14/15 because for the test I will probably be asked to use some useless fraction and I need to know how to do it. :P

Edit: Question 6.

Personally I would never use a fraction and just use more whole numbers but I have to follow what the "homework" ask for. I hate that crap but I do need to learn it for if I ever have to.

Edit 2: Right click and open in new tab will make it larger.

This post was edited by NinjaSushi2 on Mar 27 2014 04:03am
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#6
Mar 27 2014 04:07am
Quote (NinjaSushi2 @ 27 Mar 2014 10:00)
The screenshot is easy for me to read. It is 1920x1040 so I am not sure what resolution you are on. (1080 original but imgur reduced it some.)
The very bottom it says -14/15. So how do they get -14/15 because for the test I will probably be asked to use some useless fraction and I need to know how to do it. :P
Edit: Question 6.
Personally I would never use a fraction and just use more whole numbers but I have to follow what the "homework" ask for. I hate that crap but I do need to learn it for if I ever have to.
Edit 2: Right click and open in new tab will make it larger.


how would you work out a graph in more detail without using fractions if the function were 7x/(x^2-1) ?

but the answer to your -14/15 is in my first post -14/15 = -(3.5)/(3.75) = -0.9333... [7*1/2 = 3.5 and (1.2)^2-4=-3.75]

you gotta learn to love fractions :) that will make life easier

never forget the simple rule (a/b) / (c/d) = (a*d) / (b*c)

This post was edited by brmv on Mar 27 2014 04:13am
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#7
Mar 27 2014 04:11am
Quote (brmv @ 27 Mar 2014 05:07)
how would you work out a graph in more detail without using fractions if the function were 7x/(x^2-1) ?

but the answer to your -14/15 is in my first post -14/15 = -(3.5)/(3.75) = -0.9333...

you gotta learn to love fractions  :)  that will make life easier


I plotted the graph just fine but I still do not know how to get -14/15.

Here is a larger SS.

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#8
Mar 27 2014 04:21am
Quote (brmv @ 27 Mar 2014 05:07)
how would you work out a graph in more detail without using fractions if the function were 7x/(x^2-1) ?

but the answer to your -14/15 is in my first post -14/15 = -(3.5)/(3.75) = -0.9333...      [7*1/2 = 3.5 and (1.2)^2-4=-3.75]

you gotta learn to love fractions  :)  that will make life easier

never forget the simple rule (a/b) / (c/d) = (a*d) / (b*c)



OMG.. I forgot about that rule. *Derp face* :wallbash:

The derp train has left the station.

This post was edited by NinjaSushi2 on Mar 27 2014 04:22am
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#9
Mar 27 2014 04:31am
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#10
Mar 27 2014 04:36am
This post is a violation of the site rules and appropriate action was taken.

Quote (Azrad @ Mar 27 2014 04:31am)
http://s14.postimg.org/uyicq5dox/frac.png


Code
def AzradGetOnSteam(x):
gay = 7*2
wad = x**2 - 4
fractionsarefags = gay / wad
print float(fractionsarefags )


AzradGetOnSteam(-5)
AzradGetOnSteam(-1)
AzradGetOnSteam(0.5)
AzradGetOnSteam(1)
AzradGetOnSteam(5)


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