function ret = FOC_Example6_1(x)
%%% the derivatives of f wrt x1,x2
%%% or the FOC for Example 6.1
% f= 3*(sin(0.5+0.25*x(2).*x(1))).*cos(x(1));
%ret(1) = 3/4*cos(1/2+1/4*x(1)*x(2))*x(2)*cos(x(1))-3*sin(1/2+1/4*x(1)*x(2))*sin(x(1));
%ret(2) = 3/4*cos(1/2+1/4*x(1)*x(2))*x(1)*cos(x(1));
ret(1) = 2*(x(1)-1.5*x(2));
ret(2) = -3*(x(1)-1.5*x(2)) + 2*(x(2)-2);
