how can ı use find code in graph

f='(x-1)^2*(x-2)*(x-3)';
g='2*(x-1)*(x-2)*(x-3)+(x-1)^2*(x-3)+(x-1)^2*(x-2)';
xx=0:0.01:3.5;

for z=1:length(xx)
    ff(z)=feval(inline(f),xx(z));
     gg(z)=feval(inline(g),xx(z));
  
end
a=10^(-10);
figure(1)
plot(xx,ff,'k','linewidth',2);
hold on 
plot(xx,gg,'k-.','linewidth',2)
legend('f(x)','g(x)')
axis([min(xx) max(xx) -2 2])
xlabel('x')
plot(z(find(abs(gg)<a),ff(find(abs(gg)<a),'ro','ro'));

ı want to find min and max point in function

[darova]

What about peaks function?