# Need help with complex integral

1. Sep 24, 2009

### nemanja

Hi,i would be gratefull if anyone could help me with this problem.

$$\frac{2}{\pi}$$$$\int \frac{cos(ux)}{\sqrt{x}} dx$$
x goes from zero to infinity.

2. Sep 24, 2009

### CompuChip

Assuming you know a thing or two about Gaussian integrals, you could try substituting $y^2 = x$...

3. Sep 24, 2009

### nemanja

yes I tried that and I got$$\frac{\sqrt{2}}{\sqrt{u\pi}}$$
but correct is $$\frac{1}{\sqrt{u}}$$ .
any other way of solving?

4. Sep 24, 2009

### nicksauce

Are you sure 1/√u is correct? Maple and wolfram alpha agree with your answer.

5. Sep 24, 2009

### nemanja

Ok my mistake,thank you all.Maple rules