00:01
This i want to integrate and here you were told in the question to let u equal the square root of x.
00:08
So, du by dx will be one half x, negative one half, or one over two root x.
00:21
Which means then that dx will equal to root x, d .u.
00:30
Back up to here then i get the integral of becomes e to the negative u and the dx will be to root x to you.
00:51
Now the root x was u of course so we now have two integral of u the negative u to u.
01:02
Just replace the root x by u.
01:06
Now this i can do by parts.
01:11
So this will be, well, i can't use you here.
01:17
So let's call that, i'll should call this a.
01:23
And this one, dv by dx, if you like.
01:36
Or better still, actually...