clear,clf
a=-8;b=12;n=300;xx=linspace(a,b,n);
h=sin(xx+cos(xx));
S(1)=0;
for i=2:n
    S(i)=S(i-1)+quad('sin(xx+cos(xx))',xx(i-1),xx(i));
end
subplot(1,2,1),plot(xx,S,'k-'),axis([a,b,-1.5,9])
subplot(1,2,2),plot(xx,[h;zeros(1,length(xx))],'k-'),axis([a,b,-1.5,1.5])