MHB What Is the Value of the Integral $\int_0^1 xe^x \, dx$?

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The integral $\int_0^1 xe^x \, dx$ is discussed with various potential answers provided. A suggestion is made to solve the integral using a substitution method, where $t = e^x$ transforms the integral into $\int \ln{t} \, dt$. However, it is noted that knowing the antiderivative of $\ln{t}$ is essential, otherwise integration by parts would still be necessary. The conversation highlights the challenge of solving the integral without using integration by parts. Ultimately, the discussion emphasizes the complexity of finding the value of the integral through alternative methods.
karush
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$\tiny{4.2.5}$

$\displaystyle\int^1_0{xe^x\ dx}$

is equal to
$A.\ \ {1}\quad B. \ \ {-1}\quad C. \ \ {2-e}\quad D.\ \ {\dfrac{e^2}{2}}\quad E.\ \ {e-1}$

$\begin{array}{lll}
\textit{IBP}
&uv-\displaystyle\int v' dv
&\tiny{(1)}\\ \\
\textit{substitution}
&u=x,\ v'=e^x
&\tiny{(2)}\\ \\
\textit{calculate}
&I=xe^x-\displaystyle\int \ e^xdx\biggr|^1_0
=xe^x-e^x\biggr|^1_0=1
&\tiny{(3)}
\end{array}$

ok I think this is ok possible typos
but curious if this could be solve not using IBP since the only variable is x
 
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$t=e^x \implies x = \ln{t} \implies dx = \dfrac{dt}{t}$

$\displaystyle \int xe^x \, dx = \int \ln{t} \, dt$

If you happen to know the antiderivative of $\ln{t}$ off the top of your head, great ... if not, you would need to use integration by parts anyway.
 

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