function s=traprl(a,b,m)
h=(b-a)/m;
s=0;
for k=1:(m-1)
    x=a+h*k;
    s=s+f(x);
end
s=h*(f(a)+f(b))/2+h*s;
disp('****** this is the integral using trapozoidal formula  *************')
s