>

restart;

>	w := Sum((-1)^n*z^n/(n!)^2, n=0..N);

>	with(plots):

>

>	plot(eval(w,N=20), z=0..20):plot(eval(w,N=10), z=0..20, color=black):display(%%,%);

>

N := 40:

>	z2 := fsolve(w, z=8);

>	z1 := fsolve(w, z=2);

>	L := 1: g := 9.8:

>	w1 := sqrt(g*z1/L):w2 := sqrt(g*z2/L):

>	w := unapply(w, z):

>	w(x/L*zk);

>	plot([w(x/L*z1),  w(x/L*z2)],x=0..L);

>

>	animate([cos(w1*t)*w(x/L*z1), x,x=0..L],t=0..3, frames=50);

>

>	animate([cos(w2*t)*w(x/L*z2), x,x=0..L],t=0..3, frames=50);

>	animate([cos(w1*t)*w(x/L*z1)+1*sin(w2*t)*w(x/L*z2),x, x=0..L],t=0..5, frames=100);

>

>