f=inline('x^3-30*x^2+2552');
a=0;
b=19;
options=struct('TOLX',1e-7,'Display','iter');
[xb,fxb,flagb,outb,xvetb]=bzero(f,[a b], options);
[xs,fxs,flags,outs,xvets]=szero(f,[a b], options);
[xbs,fxbs,flagbs,outbs,xvetbs]=bszero(f,[a b], options);
df = inline('3*x^2-60*x');
[xn,fxn,flagn,outn,xvetn]=nzero(f,df,b, options);

xs = xvetbs(end);
semilogy(1:length(xvets),abs(xvets-xs),'r*',1:length(xvetbs),abs(xvetbs-xs),'o',1:length(xvetb),abs(xvetb-xs),'+',1:length(xvetn),abs(xvetn-xs),'d');
