# Help with this integral

Discussion in 'Math' started by u-will-neva-no, May 16, 2011.

1. ### u-will-neva-no Thread Starter Member

Mar 22, 2011
230
2
Hello

Im having trouble with this integral, and im sure there is a way to do it quickly...anyway, here is the equation:

$\frac{1-y}{3} e\frac{(1-y)^2}{2} dy$

I want to do the *trick* where you start with y = and then diffentiate and then just change the y = formula...but I cant remember how to do it...

2. ### t_n_k AAC Fanatic!

Mar 6, 2009
5,448
782
make a substitution of a new variable such that ...

v={(1-y)^2}/2
dv=?? dy

and so on ....

u-will-neva-no likes this.
3. ### galoisxss New Member

Jun 26, 2011
1
0
$\frac{(1-y)}{3}$e$^{\frac{(1-y)^{2}}{2}}$dy=-$\frac{1}{3}$∫e$^{\frac{(1-y)^{2}}{2}}$d($\frac{(1-y)^{2}}{2}$)

make a substitution of a new variable such that ...

v=$\frac{(1-y)^{2}}{2}$
that will be
-$\frac{1}{3}$∫e$^{v}$dv

and so on ....