# I Calculus of Variations Dependent variables and constraints

1. Apr 20, 2016

### shedrick94

If we have a function:

$$f(x,x',y,y',t)$$ and we are trying to minimise this subject to a constraint of
$$g(x,x',y,y',t)$$

Would we simply have a set of two euler lagrange equations for each dependent variable, here we have x and y.

Would we insert f(x,x',y,y',t)-Ag(x,x',y,y',t) into both equations, where A is a constant? Or would each equation require a different constant in front of the constraint term g(x,x',y,y',t)??

2. Apr 21, 2016

### drvrm

pl. give explicit eq of constraint -that will define the set of generalized coordinates.