multi_trapezoid

%multi_trapezoid
syms x
fx =x^2+x+2;
a = 0;
b = 2;
fy = int(fx,x);
fya = subs(fy,x,a);
fyb = subs(fy,x,b);
hs = fyb-fya
fxa = subs(fx,x,a);
fxb = subs(fx,x,b);
n = 100;
h = (b-a)/n;
fd = 0;
for i=1:(n-1)
c = a+i*h;
fxc = subs(fx,x,c);
fd = fd+fxc;                                   
end
hk = h/2*(fxa+fxb+2*fd)
ea = abs((hs-hk)/hs)