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Uuuh... Calculus...
Posted: Wed Oct 03, 2012 5:15 pm
by MrLRG
So I have this calculus class, and I was assigned this problem.
I've been stuck on it for.... 4-5 hours or so, and was curious if anyone here has the mathematical skill to actually explain it to me. I feel like I'm just overlooking something stupid. I've asked a couple of people, and I'm really starting to get annoyed.
Here's the problem:
(At school, had to use MS paint)
So, (in case you can't read that), it says the limit as x approaches 0 of f(x) of ([1/sqrt(x+1)]-1)/x
Re: Uuuh... Calculus...
Posted: Wed Oct 03, 2012 5:25 pm
by The Phantom
...You do realize that MS Paint has a "text" tool, right?
Anyways, just put it into Wolfram Alpha, came out as:
(no result found in terms of standard mathematical functions)
Re: Uuuh... Calculus...
Posted: Wed Oct 03, 2012 5:27 pm
by Dabir
Fffffffffffffffffffucking calculus.
Are you sure you're reading it right? Did you copy it from somewhere, and are you sure you copied it right?
Basically, substitute 0 for x and you end up with 0/0. This is patently retarded.
Re: Uuuh... Calculus...
Posted: Wed Oct 03, 2012 5:42 pm
by AlexMdle
You cant substitute 0 or -1 for x in that problem due to impossibility of diving/taking square root of zero.
This is quite special as I recall. Basically, try drawing that on a coordinate system and you will get a huge fucking gap where those numbers ought to be.
Re: Uuuh... Calculus...
Posted: Wed Oct 03, 2012 6:43 pm
by Dabir
What Alex said. The impossible substitutions are the vertical asymptotes. Still not sure what you're supposed to be finding, though.
Re: Uuuh... Calculus...
Posted: Thu Oct 04, 2012 2:17 pm
by [][][][]
The left... I'm not sure.
f(x) = (1/sqrt(x+1) - 1) / x...
Please clarify the left text.
Re: Uuuh... Calculus...
Posted: Thu Oct 04, 2012 4:53 pm
by Dabir
Means "the limit, as x tends to 0".
Re: Uuuh... Calculus...
Posted: Thu Oct 04, 2012 5:05 pm
by AlexMdle
To correct myself, you can take square root of zero, just not that of a negative number.
Re: Uuuh... Calculus...
Posted: Thu Oct 04, 2012 6:11 pm
by Firefox11
Imaginary numbers.
Meet your new God i.
Re: Uuuh... Calculus...
Posted: Mon Oct 08, 2012 4:40 pm
by MrLRG
Found out you have to rationalize the numerator and then do some crap to rationalize the denominator. Came out with -.5 as the answer. >_<