Answer
$$\lim_{t\to 0} h(t)=-0.5$$
Work Step by Step
Given
$$ h(t)=\frac{\cos t-1}{t^{2}} $$
Since
\begin{array}{|c|c|c|c|c|}
\hline
t & \pm0.002 & \pm0.0001 & \pm0.00005 & \pm0.00001 \\ \hline
h(t) & -0.499999833 & -0.499999997 & -0.499999997 & -0.500000041 \\ \hline
\end{array}
Then
$$\lim_{t\to 0} h(t)=-0.5$$