kill(all);

van=facebook.com/LearningCalculus$

f(x):=(sqrt((4-x)^3) + %e^x -9)/x;

g(x):=fullratsimp(f(x))$ g(x);

h(x):=factor(g(x))$ h(x);

u=sqrt(4-x);

x=4-u^2;

h(4-u^2);

limit(h(4-u^2),u,2);