# Simple Double Integral Question

• Jul 4th 2010, 03:21 PM
thepongofping
Simple Double Integral Question
I need to evaluate this integral

$\iint\limits_{D} {\frac{1}{\sqrt {x^{2}+y^{2}} }}dA$

over the area bounded by the top half of (x-1)² + y² =1.

My calculation keeps yielding 2, but this does not make logical sense because the area is a half circle of radius 1. Shouldn't the value of the integral be Pi/2 ?

Anybody else get 2 from the integral?
• Jul 4th 2010, 05:31 PM
xxp9
why do you think $\int_D \frac{1}{\sqrt{x^2+y^2}}dA$ is the area? Actually $\int_D dA$ is the area, but your integral is not.