Optimization Response using function and equation commands

Hi all, 

 

I am using Hypermesh for a topology optimization and have to define a function response for my dconstraint. 

Three questions came up and I were unable to find anything in the Internet:

 

1. Which Syntax is used for the dequation? Or has anybody a list with commands? I can not figure out how to apply a power because this is not working: ^

 

2. I created two responses x and y, which I would like to include into a third response using a function. When I define a equation f(x,y) = sqrt(x^2+y^2) and create a response with this equation, how do I link the responses x and y to the equation?

 

3. What is the diffrence between DRESP2, DRESP2V and DRESP2LV?

 

Thank you all in advance and please excuse my lack of knoowledge, I am still learning.

 

Best, 

Timo