# Homework Help: How to convert velocity potential from polar form to Cartesian coordinate form!

1. Nov 6, 2011

### rohitgupta

1. The problem statement, all variables and given/known data
Alright, here's the question, A stream function for a plane, irrotational, polar-coordinate flow is ψ=9r^2sin^θ. Find out the velocity potential in Cartesian Co-ordinate!

2. Relevant equations

3. The attempt at a solution
Well, I can easily find out the velocity potential in Polar co-ordinates but then how do I convert it to Cartesian Co-ordinates?

2. Nov 6, 2011

### rude man

There are standard formulas for doing that, in most 2nd-year engineering course textbooks.

3. Nov 7, 2011

### rohitgupta

Well I did try searching for it in Fox&Mcdonald(the book that I follow), I didn't find it there, maybe I have overlooked it but anyways could you please give me a link or type the formulas here.

Thank You.

4. Nov 7, 2011

### rude man

5. Nov 23, 2011

### mccoy9704

would you mind answer this... find the polar form of 1/4i and also 1/z? please give the answer..