# I What does this notation mean?

1. Jul 14, 2016

### lucdj3

Can you help me figure out what the equation in the attached image means?
What I do know is: h(p) is a Monge parameterization height function depending on radius (p), this is a boundary condition for a differential equation, and p0 is the outer boundary, with the inner boundary creating a boundary condition of h(pi)=0.
Thanks!

#### Attached Files:

• ###### biharmonicboundarycondition.png
File size:
1.2 KB
Views:
68
2. Jul 14, 2016

### lucdj3

I wasn't sure where this thread should be posted, so if there would have been a better place, please let me know and I will re-post there

3. Jul 14, 2016

### Mr-R

To me this read: The partial derivative with respect to $\rho$ evaluated at $\rho=\rho_0$.
As in take the derivative first and then set $\rho=\rho_0$.
I could be wrong though.

4. Jul 15, 2016

### lucdj3

That seems reasonable. Short term it is yielding something that doesn't look wrong, once I get through everything else I'll be able to tell if it's right. Thanks!
Any idea why it wouldn't be d/dp as the operator out front?

5. Jul 15, 2016

### Mr-R

Maybe the author is being sloppy because it looks like it only depends on $\rho$ and therefore it could be derived with $\frac{d}{d\rho}$.

6. Jul 15, 2016

### lucdj3

Well it worked it, thanks!