# Thread: Notation Question

1. ## Notation Question

What is meant by this notation

$u(x,y;\lambda)\mbox{?}$

Thanks.

2. It usually means there's some parameter $\lambda$ in the solution $u(x,y)$ (if it's in the context of the solution of a differential equations which I think has been the focus of some of your lasts posts).

3. If you wouldn't mind, can you show me an example of this?

It can be as simple as possible.

4. Surely a family of functions $\{u_{\lambda}:A\subset\mathbb{R}^2\rightarrow \mathbb{R}\}$

Example:

$u_{\lambda}(x,y)=\lambda^2\sin (x^3y)$

Fernando Revilla

Edited: Sorry, I didn't see Danny's post.

5. Originally Posted by dwsmith
If you wouldn't mind, can you show me an example of this?

It can be as simple as possible.
Do you know the Lagrange Mulitplier method for optimisation?

6. Like when you have an equation, constraint, and your goal is to maximize or minimize?

7. yep.

8. I don't see how they related though. I am not saying they aren't I just don't see it. Well, besides that lambda is used in the Lagrange Multiplier.