kill(all);

van=facebook.com/LearningCalculus$

e(x):=(x-1)^(1/(x-1)) - (x+1)^(1/(x+1));

e(x)=0;

e(3);

e(x^3)=0;

e(x)=-3/2;

e(e(x))=3;

limit(e(x)=0,x,3);
f(u):=(log(u)/u)$
is(equal(f(2),f(4)));