The function has a discontinuity at 
. From the plots below, the integral cannot converge in the interval 
. From the plots below, the integral cannot converge in the interval syms z
f = exp(z*(z + 1)/(z - 1));
subplot(121)
fplot(f, [-7, 1])
xlabel('z')
title('f(z < 1)')
ylim([0, 1.2])
subplot(122)
fplot(f, [1, 3])
xlabel('z')
title('f(z > 1)')
ylim([0, 5000])
