kill(all)$

van=facebook.com/LearningCalculus$

f(x):=   x^2 - sqrt(x)$
g(x):= 1/x^2 - sqrt(x)$

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

fp(x);
gp(x);

t(x):=fp(x)=gp(x)$

limit(t(x),x, 0, plus);

s:solve(t(x),x)$
rectform(s[1]);
rectform(s[2]);
rectform(s[3]);
rectform(s[4]);

2*x +2/x^3;