Trajectory example from class, this is the cannon trying to hit a target

40*tan(theta)-(2.45)/(cos(theta)^2)-1;

th:find_root(%, theta, -1, 1);

float((th/%pi)*180);

10/cos(th);

wxplot2d([['parametric, 800*t*cos(th), 800*t*sin(th)-4.9*t^2, [t, 0, 10.04], [nticks, 300]]], [x,0,8000], [y,0,500])$