function y = F(x)
% Right hand side function.
%
% INPUT: x (current point)
%
% OUTPUT: y (right hand side value at given point x and time t)
%
y = zeros(6,1);
y(1) = 1;
y(2) = x(3);
y(3) = sqrt(6/(1+x(2)^2))-1/(2+x(4)^2) + sin(x(1)) - 2*cos(x(3)*x(6));
y(4) = x(5);
y(5) = x(6);
y(6) = -sqrt(4/(1+x(2)^2))-1/(1+x(4)^4) + cos(x(1)) + sin(x(2)^2*x(5));

