euler

syms x y
fxy= -2.2067*10^-12*(y^4-81*10^8)*h;
a= 0;
b=480;
n=10;
h= (b-a)/n;
x1= a;
y1= 1200;
ys= 647.57; %nilai sebenarnya
es=1;
N=[x1 y1 es ];
for i=1:n
    y2= y1+ subs (fxy,{x,y},{x1,y1});
    x2= x1+h;
    es= abs ((ys-y2)/ys);
    N= [N;x2 y2 es ];
    x1=x2;
    y1=y2;
end
N