kill(all)$

van = facebook.com/LearningCalculus;

f(x):=(1-x)/(1+x);

fp(x):=''(diff(f(x),x));
gp(x):=''(diff(g(x),x));
fp(x)/gp(x);

fp(x)/gp(x);

limit(fp(x)/gp(x),x,0);