1. ## Integration by Parts?

$\displaystyle \int_0^1 (1-t) e^{-st} dt$

[tex]
\int_0^1 e^{2t-st} dt
[\math]

2. Originally Posted by diddledabble
$\displaystyle \int_0^1 (1-t) e^{-st} dt$
[tex]
\int_0^{\infty} e^{(2-s)t} dt
[\math]
$\displaystyle u = 1-t$
$\displaystyle \frac{du}{dt} = -1$

$\displaystyle \frac{dv}{dt} = e^{st}$
$\displaystyle v = \frac{1}{s}e^{st}$

That -1 should mean only one iteration is needed

3. Originally Posted by diddledabble
$\displaystyle \int_0^1 (1-t) e^{-st} dt$

$\displaystyle \int_0^1 e^{2t-st} dt$

$\displaystyle \int\limits_0^1 {\left( {1 - t} \right){e^{ - st}}dt} = - \frac{1} {s}\int\limits_0^1 {\left( {1 - t} \right)d\left( {{e^{ - st}}} \right)} = \left. { - \frac{{{e^{ - st}}}}{s}\left( {1 - t} \right)} \right|_{t = 0}^{t = 1}$$\displaystyle + \frac{1}{s}\int\limits_0^1 {{e^{ - st}}d\left( {1 - t} \right)} =$

$\displaystyle = \left. { - \frac{{{e^{ - st}}}}{s}\left( {1 - t} \right)} \right|_{t = 0}^{t = 1} - \frac{1}{s}\int\limits_0^1 {{e^{ - st}}dt} = \left. { - \frac{{{e^{ - st}}}}{s}\left( {1 - t} \right)} \right|_{t = 0}^{t = 1} + \frac{1} {{{s^2}}}\int\limits_0^1 {d\left( {{e^{ - st}}} \right)} =$

$\displaystyle = \left. {\left( { - \frac{{{e^{ - st}}}}{s}\left( {1 - t} \right) + \frac{{{e^{ - st}}}}{{{s^2}}}} \right)} \right|_{t = 0}^{t = 1} = \frac{{{e^{ - s}}}}{{{s^2}}} + \frac{1}{s} - \frac{1}{{{s^2}}} = \frac{1} {{{s^2}}}\left( {{e^{ - s}} + s - 1} \right).$

4. I tried typing this one in Latex but it wouldn't come out.

[tex]
\int_0^1 e^{(2-s)t} dt
[\math]

5. Originally Posted by diddledabble
I tried typing this one in Latex but it wouldn't come out.

[tex]
\int_0^1 e^{(2-s)t} dt
[\math]
/math not \math

6. ## Is this also by parts?

$\displaystyle \int_0^1 e^{(2-s)t} dt$

7. Originally Posted by diddledabble
$\displaystyle \int_0^1 e^{(2-s)t} dt$
It's not by parts

$\displaystyle \int\limits_0^1 {{e^{(2 - s)t}}dt} = \frac{1}{{2 - s}}\int\limits_0^1 {d\left( {{e^{(2 - s)t}}} \right)} = \left. {\frac{{{e^{(2 - s)t}}}}{{2 - s}}} \right|_{t = 0}^{t = 1} = \frac{{{e^{2 - s}} - 1}}{{2 - s}}.$