clear %% f = @(x) 1./(1+x.^2); x = @(t) sinh(pi*sinh(t)/2); chain = @(t) pi/2*cosh(t).*cosh(pi*sinh(t)/2); integrand = @(t) f(x(t)).*chain(t); fplot(integrand,[-4 4]) set(gca,'yscale','log') xlabel('t') ylabel('f(x(t))') title('Doubly exponential integrand decay') grid on %% % This graph suggests that we may integrate $t$ from $-4$ to $4$ and % capture all of the integrand values that are larger than machine epsilon.