# Math Help - Evaluate the integral?

1. ## Evaluate the integral?

let A = ρ sinφ aρ + ρ2 aφevaluate ∮L A.dl for the contour L as show in the figure, please see attachment and guide me in detail. Thanks.

2. ## Re: Evaluate the integral?

Well what are your parameterisations for each part of the contour?

4. ## Re: Evaluate the integral?

You must have done similar problems to this one in class and in your notes. The first step is to find a parameterisation for each part of the contour, then sum the integrals that you get from each part of the contour.

5. ## Re: Evaluate the integral?

I did such questions like an year ago and now i have forgotten.........can you recommend any book or webpage?

6. ## Re: Evaluate the integral?

Two legs are straight lines lying on the x-axis. Do you see that the angle $\Phi$ does not change, and only $\rho$, the distance from the origin does? Two of the legs are semi-circles with center at the origin. Do you see that $\rho$, the distance from the origin, does not change and only $\Phi$, the angle, changes?

7. ## Re: Evaluate the integral?

yeah thats great.....i can see that, what next.....just give me a startup for the calculations...i can hanlde the integration...i am just stuck with the............ formation of what to integrate!!!