% matlab code
% use trapezoidal method for integration
f=inline("cos(10*x)");
x0=-1;
x1=1;
N=10000;
dx=(x1-x0)/N;
S=0.0;
for i=1:N
xx1=x0+dx*i;
xx2=x0+dx*(i-1);
S=S+0.5*(f(xx1)+f(xx2))*dx;
end
err=sin(10)/5-S;