How to add a constraint in lsqonlin minimization?

In the optimization problem below, I obtain a (1x5) vector x. I want to put the following additional constraint : 2*x(2)*x(3)>x(4)^2, such that the obtained vector x satisfies this constraint. Does someone knows how to do this? Help is very much appreciated.

x0=[.5, 50, .5, .5, 0];

lb = [0, 0, 0, 0, -1];

ub = [1, 100, 1, 1, 1];

x = lsqnonlin(@fun,x0,lb,ub);

Answer 1

[Alan Weiss]

For that kind of nonlinear constraint, use fmincon instead of lsqnonlin. See the Optimization Decision Table.

Alan Weiss

MATLAB mathematical toolbox documentation