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Dogmeat
post Aug 6 2007, 03:52 PM
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DEATH TO ....something?


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Ok, this is embarassing, but Calc II was far and away my worst subject in all of college.

Let's say you have a 1/x function and you actually need to integrate this for a purpose instead of just for fun, so you have limite of integration on it.

considering the integral of 1/x is ln (x) ...

what do you do again if one of your limits of integration is 0 ...?

mathematically you get infininty if you integrate this because the ln of 0 is infinity .... BUT.

I actually need to figure out a way to quantify this equation for a useful purpose believe it or not.

All my old calc books are still packed up so I can't go look at them and I can't find a tutorial on the internet.

Help! I'm retarded!


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prefix
post Aug 15 2007, 03:14 PM
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Mathematics grad student to the rescue. You can't integrate it with the bottom limit of zero, you'll get infinity. If you're doing something where you're integrating to 0 then you're probably doing it wrong. Perhaps you could explain the problem and I should be able to help you out.

A little explanation. Since you have a bound that doesn't exist you actually take the limit of the integral from N to whatever and then evaluate with the limit of N approaching 0. But once again you'll get

lim N -> 0 [ ln(l) - ln(N) ] = ln(l) - (-inf). Where l is your upper bound. I'd use b as your bound but it keeps making smiley faces like this cool.gif
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blaarg
post Aug 16 2007, 03:07 PM
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QUOTE (prefix @ Aug 15 2007, 04:14 PM) *
Mathematics grad student to the rescue.


Wait your a math grad student...
uh who are you?


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Posts in this topic
- Dogmeat   Math Retard Question   Aug 6 2007, 03:52 PM
- - 1up   dude, go buy a ti-89 and use the integration funct...   Aug 6 2007, 04:15 PM
|- - Dogmeat   QUOTE (1up @ Aug 6 2007, 04:15 PM) dude, ...   Aug 6 2007, 04:24 PM
- - Spectatrix   The integral would be infinity. *shrugs* But app...   Aug 6 2007, 06:24 PM
|- - Dogmeat   QUOTE (Spectatrix @ Aug 6 2007, 06:24 PM)...   Aug 6 2007, 06:34 PM
- - Jessica   yet another area in which my philosophy degree has...   Aug 6 2007, 11:05 PM
|- - FORSAKENR320   QUOTE (Jessica @ Aug 7 2007, 12:05 AM) ye...   Aug 7 2007, 01:44 AM
|- - Dr. Gonzo   QUOTE (FORSAKENR320 @ Aug 7 2007, 02:44 A...   Aug 13 2007, 08:15 PM
|- - FORSAKENR320   QUOTE (Dr. Gonzo @ Aug 13 2007, 09:15 PM)...   Aug 13 2007, 08:26 PM
- - chook   so, why were you trying to integrate the area?   Aug 6 2007, 11:41 PM
- - impala454   ooh ice-burn and dogmeat what in God's name a...   Aug 7 2007, 08:38 AM
- - schwab   i got a masters in engineering...and still i dont ...   Aug 13 2007, 08:36 PM
|- - FORSAKENR320   QUOTE (schwab @ Aug 13 2007, 09:36 PM) i ...   Aug 14 2007, 04:20 AM
- - Dr. Gonzo   That is probably a bad thing, yes?   Aug 13 2007, 11:04 PM
- - prefix   Mathematics grad student to the rescue. You can...   Aug 15 2007, 03:14 PM
|- - blaarg   QUOTE (prefix @ Aug 15 2007, 04:14 PM) Ma...   Aug 16 2007, 03:07 PM
- - impala454   damn math majors... too worried about solving the ...   Aug 16 2007, 03:33 PM
- - prefix   I am a person who is anonymous on the internet wit...   Aug 16 2007, 06:53 PM
- - James   Wow. What's up with all the math grad student...   Aug 17 2007, 01:21 AM
- - moebary   nah, got my undergrad in math but i'm an atmo ...   Aug 17 2007, 08:40 AM


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