Question 467474
{{{log(3, (-1))}}} is not defined because if we let {{{log(3, (-1)) = w}}}, then exponentially we would have {{{3^w = -1}}}, BUT the term on the left is always positive, and so equality is impossible.

{{{log(1, 1)}}} is undefined because  if we let {{{log(1, 1) = w}}}, then exponentially we would have {{{1^w = 1}}}, and there would be infinitely many possible answers for w.