Solving a Double Integral: Int[1 to 2] Int[0 to x] of 1/(sqrt((x^2)+(y^2)))dydx

[FecalFrown]

Homework Statement

Howdy fellas, long time lurker, first time poster. If someone could get me started on the right track for this problem, it would be appreciated.

Also, I'm not sure how to write equations yet, but I'll do my best to explain the problem clearly

Homework Equations

Int[1 to 2] Int[0 to x] of 1/(sqrt((x^2)+(y^2)))dydx

The Attempt at a Solution

As I said, not sure how to get started. My gut was telling me to raise the denominator to the -1/2 power and use the substitution rule? But I'm not sure.

Thanks

 

[micromass]

Hi FecalFrown!

Let's start with the inner integral, this is

$$\int_0^x{\frac{1}{\sqrt{x^2+y^2}}dy}$$

where x is simply a constant. The trick is to factor x out of the square root, and then to do a trigonometric substitution $\frac{y}{x}=\tan(\theta)$