TeX source:
\begin{array}{rclll} f''(t) &=& \dfrac{6t^4-22t^3+30t^2-18t}{(t-1)^3} \cr\cr f''(0) &=& \dfrac{6 \cdot 0^4-22 \cdot 0^3+30 \cdot 0^2-18\cdot 0}{(0-1)^3} \quad = \quad 0\end{array}