function l1_5()
clear all
tic 
x=0:2*pi/10000:2*pi;
y=exp(-x.^2).*cos(x);
toc
tic
for i=1:10001
c(i)=2*pi/10000*(i-1);
d(i)=exp(-x(i)^2)*cos(x(i));
end
toc
