# Math Help - Integrating in the cylindrical coordinate system

1. ## Integrating in the cylindrical coordinate system

Hi everyone please see the problem below:

Im trying to learn how to evaluate 3a. NOTICE: ap is a vector(boldfaced). My prof vagely mentioned something about not being able to integrate directly since as the direction of phi chances so does the direction ap. I know this seems unclear as this has me confused aswell and i cant find any information in my text regarding this. Can someone please help me understand how to integfrate this?

(p, phi , z)
p = radial distance from z-axis
phi = angle in radians meansured from "x-axis"
z=z as in cartesian.

Thank you!

2. ## Re: Integrating in the cylindrical coordinate system

I should also add, this has applications in field Theory or Electromagnetics if that help clarify the question.

3. ## Re: Integrating in the cylindrical coordinate system

Is anyone able to suggest anything I can read for the above problem?

4. ## Re: Integrating in the cylindrical coordinate system

Not without knowing what $a_\rho$ is!

5. ## Re: Integrating in the cylindrical coordinate system

Originally Posted by HallsofIvy
Not without knowing what $a_\rho$ is!
ap is the vector pointing in the p direction, where:
(p, phi , z)
p = radial distance from z-axis
phi = angle in radians meansured from "x-axis"
z=z as in cartesian.

6. ## Re: Integrating in the cylindrical coordinate system

Is anyone able to suggest anything I can read for the above problem?