function EulerMethod3
grid on
x0=0;
y0=2;
h=0.01;
b=5;
x=[];y=[];
x(1)=x0;
y(1)=y0;
for j=1:(b-x0)/h
    x(j+1)=x(j)+h;
    y(j+1)=y(j)+h*ff(x(j),y(j));
end

    function z=ff(x,y)
        z=-20*y+20*x+21;
    end
plot(x,y)
[T,Y]=ode15s(@ff,[x0,x0+5],y0);
end

