a=0;b=1;n=64;h=(b-a)/n;
>> x(1)=0;
>> for i=2:n+1
x(i)=(i-1)*h;
end
>> for i=1:n+1
f(i)=exp(-x(i));
end
>> f(65)
ans =  0.367879441171442
>> exp(-1)
ans =  0.367879441171442
>> w(1:n+1)=ones(1);
>> w(2:2:n)=4;
>> w(3:2:n-1)=2;
>> for i=1:65
end
>> s=0
s = 0
>> for i=1:n+1
s=s+f(i)*w(i)*h/3;
end
>> s
s =  0.632120559037870