fsolve or local optimum?

Hello,

I have a nonlinear algebraic equation system: f(x,t)=0 (where f ist a vector field and x a vector, t is the time.)

My Problem:

f(x,t)=0 and a second (one-dimensional) determinant equation det(jacobian(f,x))=0 have the same solution x, for a certain time t. How can I get x and t ? What I know is that x is a Local optimum of f(x,t) and if you want, with the constrain det(jacobian(f,y))=0. And my initial point x0 is near the solution x.

I hope someone has an idea. Thank you!

[Sargondjani]

it seems you can use both fsolve and fmincon. i would prefer fsolve i suppose, but why not try both? it shouldnt take much extra time to try the other as well...

[Kim O]

Thank you for your opinion. I will try both and then I will post my results. Maybe I am succesfull with both methods :) or maybe not ;(