The problem reads:
Find parametric equations for the tangent line to the curve with the given parametric equations at the specified point: $x = \ln(t), y = 2\sqrt{t}, z = t^2$; $(0, 2,1)$.
It seems to me that, since $x = \ln(t)$, the curve is not defined at any point where $t = 0$. Am I missing something obvious? Is there some way of defining the tangent line to the curve at a point even when the curve is not defined there?