% Problem # 4 (Gaffney's or Cornelius-Lohner's Function)
% Range of initial points: 1.9 <= x <= 3.9
% Global maxima: x=2.868033983115523
% f(x)=3.850450708800221
% Coded by: Ali R. Alroomi | Last Update: 14 Feb. 2015 | www.al-roomi.org
 
clear
clc
warning off
 
xmin=1.9;
xmax=3.9;
R=100000; % steps resolution
x=xmin:(xmax-xmin)/R:xmax; 
 
for i=1:length(x)
    f(i)=(16*x(i)^2-24*x(i)+5)*exp(-x(i));
end
 
plot(x,f,'r','LineWidth',2);grid;set(gca,'FontSize',12);
xlabel('x','FontName','Times','FontSize',20,'FontAngle','italic');
ylabel('f(x)','FontName','Times','FontSize',20,'FontAngle','italic');