x 1e-3 3e5 2d
0 .6 .5 .2
x[1]^2-.42*x[1]*cos(x[0])
(x[1]*cos(x[0])-x[3]*cos(x[2]))^2+(x[1]*sin(x[0])-x[3]*sin(x[2]))^2
x[3]-.2*cos(7*x[2]/4)