Re: Calculus (Substitution)...


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Re: Calculus (Substitution)...



At 09:48 PM 11/12/98 -0500, Thomas J. Hruska wrote:
>Help!  I have an integral that I can't work either forward or backward.
>
>Here is the problem (S = integral sign):
>
>S (e^x - 3)^(1/2) dx
>
>
>The problem states that I have to use substitution, so:
>
>u = e^x - 3
>du = e^x dx
>du / (e^x) = dx
>du / (u + 3) = dx
>
>S [u^(1/2) / (u + 3)] du
>
>That is as far as I have gotten.  If someone could please help me finish
>this problem I would be very grateful.  My dad's own calculus books don't
>help with this problem either.  TIA

I cant help with the process, but I can give you an answer to work towards:

2*sqrt(e^x-3)-2*sqrt(3)*atan(sqrt(3*(e^x-3))/3)

thats what my TI-89 says the answer is (you can add +C to the end if you
want this as an anti-derivative)

--
Bill Risher        Sparr      UIN:1952775    ._, . . .
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Overlord n7hq      Decius                    |_) | | |
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