%   Figure 11.1   s11fig1.m
clear
hold off
x= 0:0.1:10;
z= 0*x;
%y=tan(x);
axis([0 16 -30 10])
%plot(x,tan(x),'k.')

%
%
fplot('ftan',[0,10],'k');
hold
plot(x,-x,'k-')
plot(x,z,'k-')