# Notation Question

• December 26th 2010, 12:26 PM
dwsmith
Notation Question
What is meant by this notation

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

Thanks.
• December 26th 2010, 12:34 PM
Jester
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).
• December 26th 2010, 12:35 PM
dwsmith
If you wouldn't mind, can you show me an example of this?

It can be as simple as possible.
• December 26th 2010, 12:37 PM
FernandoRevilla
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.
• December 26th 2010, 12:42 PM
pickslides
Quote:

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?
• December 26th 2010, 12:43 PM
dwsmith
Like when you have an equation, constraint, and your goal is to maximize or minimize?
• December 26th 2010, 01:03 PM
pickslides
yep.
• December 26th 2010, 01:05 PM
dwsmith
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.