# Max/Min of a function using Lagrange Multipliers

1. May 20, 2009

### andrewjohnsc

1. The problem statement, all variables and given/known data
Find the absolute maximum and minimum values for f(x,y) = sin x + cos y on the rectangle R defined by 0<=x<=2pi and 0<=y<=2pi using the method of Lagrange Multipliers.

3. The attempt at a solution
I don't know where to start in getting the constraint into something I can work with!

2. May 20, 2009

### benorin

you can always use $$x+y=C$$ where $$C$$ is some constant.

3. May 20, 2009

### andrewjohnsc

I don't understand how that constrains the function to 0<=x<=2pi 0<=y<=2pi