function radice=newton(a0,b0)

a(1)=a0;
b(1)=b0;
c(1)=a0;
d(1)=b0;
k=1;
j=1;
while(b(1)-a(1))/(2^(k-1))>10^-14
    c(k+1)=c(k)-((funz(c(k)))/funz2(c(k)));
    k=k+1;
end
while(b(1)-a(1))/(2^(j-1))>10^-14
    d(j+1)=d(j)-((funz(d(j)))/funz2(d(j)));
    j=j+1;
end
radice=(c(k)+d(j))/2;