# Evaluating a Line integral in spherical polar coordinates

#### wam_mi

1. Homework Statement

Consider the vector potential
A = cr * [(sin theta)^2 * (cos fi) * (sin fi) + (cos theta)^2 ) er
+ (sin theta) cos (theta) * [(sin fi) (cos fi)  − 1] e theta
+ {(sin theta) (cosfi)^2 } efi

er: in the er direction
e theta: in the e theta direction
e fi: in the e fi direction

A is given in spherical polar coordinates.

Calculate the line integral A dot dl with closed curve C, where C is the circle parametrised by fi, at some arbitrary values of (r, theta)

It would also be nice to see a full solution!!

Can anyone please also tell me what's the general trick of tackling problems with line integral?

Many thanks guys!!!

2. Homework Equations

3. The Attempt at a Solution

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#### gabbagabbahey

Homework Helper
Gold Member
It would also be nice to see a full solution!!
3. The Attempt at a Solution
We don't provide full solutions;it's against forum policy!

As a hint, a good starting point is to find an expression for dl (after all, you are going to have a heck of a time integrating A.dl if you don't know what dl is! )....

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