Re: Correction to "Fundamental Theorem of Calculus and Mathematica"
- To: mathgroup at smc.vnet.net
- Subject: [mg100767] Re: [mg100727] Correction to "Fundamental Theorem of Calculus and Mathematica"
- From: Curtis Osterhoudt <cfo at lanl.gov>
- Date: Sat, 13 Jun 2009 06:04:10 -0400 (EDT)
- Organization: LANL
- References: <200906120144.VAA17857@smc.vnet.net>
- Reply-to: cfo at lanl.gov
Works here ("7.0 for Linux x86 (32-bit) (November 11, 2008)").
In[4]:= f[x_] := Integrate[Sin[t^2], {t, 0, x}]
In[5]:= D[f[x], x]
Out[5]= Sin[x^2]
In[6]:= g[x_] := Integrate[Exp[-t^2], {t, 0, x}]
In[7]:= D[g[x], x]
Out[7]= E^-x^2
On Thursday 11 June 2009 07:44:34 pm Len wrote:
> Greetings:
>
> I define a function (using f[x_]:=) as the definite integral (from 0
> to x) of sin(t^2). When I differentiate using Mathematica I get the
> correct answer of sin(x^2).
>
> But when I define a function (using g[x_]:=) as the definite integral
> (from 0 to x) of e^(-t^2) and differentiate, I get the incorrect
> answer of 0. (The correct answer is e^(-x^2).)
>
> Why the inconsistency?
>
> Oddly, if I define the function g above using "=" instead of ":=", all
> works well.
>
> Can someone explain the odd behavior?
>
> Thanks,
>
> Len
>
>
--
==================================
Curtis Osterhoudt
cfo at remove_this.lanl.and_this.gov
PGP Key ID: 0x4DCA2A10
==================================
- References:
- Correction to "Fundamental Theorem of Calculus and Mathematica"
- From: Len <lwapner2@gmail.com>
- Correction to "Fundamental Theorem of Calculus and Mathematica"