Solving an Integral: x^(0.5)*exp(x)dx

[smadar ha]

How can I solve the following integral:

x^(0.5)*exp(x)dx

Thanks.

 

[virus]

use integration by parts

 

[smadar ha]

I tried but it gives me another integral that I can't solve:

x^(-0.5)*exp(x)dx

 

[Hootenanny]

I tried but it gives me another integral that I can't solve:

x^(-0.5)*exp(x)dx

Now use integration by parts again, but this time swap your variables around so that you are integrating x^-0.5 and differentiating e^x.

 

[smadar ha]

if I do it I receive:

integral(x^0.5*exp(x))=integral(x^0.5*exp(x))

and it doesn't help me...

 

[Hootenanny]

if I do it I receive:

integral(x^0.5*exp(x))=integral(x^0.5*exp(x))

and it doesn't help me...

Indeed it doesn't. In that case I would suggest I substitution of the form u=x^0.5, followed by integration by parts. However, I will point out at this point that the integral probably cannot be written in terms of elementary functions and you will most likely have to make use of the error function.

 

[smadar ha]

I think that may help.

Thanks a lot.

Smadar.

 

[virus]

no you can actually solve this problem by integration by parts, just do wat hootenanny said you will have to integrate by parts twice but you would have to swap the variables in the second case...