function nt=newton(t,n)
x=[0.5 1.0 1.5 2.0 2.5];
r(1)=n0(x(1));
r(2)=n1(x(1),x(2))*(t-x(1));
r(3)=n2(x(1),x(2),x(3))*(t-x(1))*(t-x(2));
r(4)=n3(x(1),x(2),x(3),x(4))*(t-x(1))*(t-x(2))*(t-x(3));
r(5)=n4(x(1),x(2),x(3),x(4),x(5))*(t-x(1))*(t-x(2))*(t-x(3))*(t-x(4));
nt=0;
for i=1:n
    nt=nt+r(i);
end