Recent content by walking_edges

Thank you very much!

I'm trying to figure out if a given vector field is perpendicular at the surface of a sphere of radius R. The vector field is given in spherical coordinates. I initially attempted to take the cross product of the vector field with the normal vector at the surface of the sphere to see if it was...

Alright, I think I get it now. Cos (x) was merely the real part of a larger complex function. And so the integral of \int^{\infty}_{-\infty}\frac{sin\:x\:dx}{1+x^{2}} would just be zero, Since the answer to the larger complex function only has a real part to it, and sin(x)...

Homework Statement My question has two parts. The first part is the solution of the following integral: \int^{\infty}_{-\infty}\frac{cos\:x\:dx}{1+x^{2}} They give the answer as being \frac{\pi}{e} This is actually an example problem in the book, but I don't understand how...