global c q m;

c=-5;
q=-1;
m=1;
centro=[0;0];

dt = 0.0005;

t(1)=0;
y(1,1)=10.;

#plot(t(1),y(1,1),"bo","markersize",15);
#axis ([0 1 -10 15]);
#hold on;

for i=1:2000
yy=y(i,:);
tt=t(i);

for j=1:1
	yy=yy+dt*fa(tt,yy);
	tt=tt+dt;
#plot(tt,yy(1),"go","markersize",8);
endfor
t(i+1)=tt;
y(i+1,:)=yy;
#plot(t(i+1),y(i+1,1),"ko","markersize",8);
#pause;
endfor