Unheated building (Zill 1.3 #6) 0 -0.1*(y-F(x)) 0,96,24 40,120,23 euler 0.1 [0,100] F(x)=80-30cos(pi x/12);color=purple Circle -x/y -3,3,24 -2,2,16 rk4,true,0.05 [0,1] [1,1] [2,0] Undamped pendulum -sin(x)/y -2pi,2pi,24 -4,4,16 rk4,true,0.05 [0,-3] [0,2.2] [0,1] [0,2] [0,-2] Undamped pendulum (system) 2 t,y,v -sin(x)/y v -sin(y) -2pi,2pi,24 -4,4,16 rk4 0.05 [0,2] [0,1] [0,-3] [0,2.2] [0,-2] y^2=A+2cos(x);color=black Damped pendulum -0.5-sin(x)/y -pi,3pi,24 -4,4,16 rk4,true,0.01 [0,2] [0,-2] [2,2] [0,1] Damped pendulum (system) 2 t,y,v -0.5-sin(x)/y v -0.5v-sin(y) -pi,3pi,24 -4,4,16 rk4 0.01 [0,2] [0,-2] [2,2] [0,1] Predator-prey y/x*(.005x-0.2)/(0.4-0.05y) 0,100,15 0,16,15 rk4,true,0.09 [80,9] [20,4] Predator-prey (system) 2 t,r,f y/x*(.005x-0.2)/(0.4-0.05y) r*(0.4-0.05f) f*(.005r-0.2) 0,100,15 0,16,15 rk4 0.1 [80,9] [20,4] Beetles on a square (y-x)/(x+y) -3,3,21 -2,2,15 rk4,true,0.04 [1,1] [0,1] [-1,0] Beetles on a square (system) 2 (y-x)/(x+y) -x-y x-y -3,3,21 -2,2,15 rk4 0.04 [1,1] [0,1] [-1,0] r=5e^-@;color=black;amax=4pi BDH 1.3 #1 x^2+x -3,3,15 -2,2,15 euler,false,0.1 BDH 1.3 #2 1-2y -3,3,15 -2,2,15 euler,false,0.1 BDH 1.3 #3 y+x+1 -3,3,15 -2,2,15 euler,false,0.1 BDH 1.3 #4 x^2+1 -3,3,15 -2,2,15 euler,false,0.1 BDH 1.3 #5 2y*(1-y) -3,3,15 -2,2,15 euler,false,0.1 BDH 1.3 #6 4y^2 -3,3,15 -2,2,15 euler,false,0.1 BDH 1.3 #12 y(y-1)(y-1) -3,3,15 -2,2,15 euler,false,0.1 BDH 1.4 #1 2y+1 0,2,15 0,60,15 euler,false,0.5 [0,3] BDH 1.4 #2 x-y^2 0,2,15 0,2,15 euler,false,0.5 [0,1] BDH 2.1 #7 2 t,r,f y/x*(.005x-0.2)/(0.4-0.05y) 2(1 - r/3)r - r*f -2f + 4r*f 0,1.5,15 0,4,15 rk4 0.05 [1,0.3]