For the expression \(\sqrt{-14} \cdot \sqrt{-2}\), recognize that the square root of a negative number involves imaginary numbers. Use the property \(\sqrt{a} \cdot \sqrt{b} = \sqrt{a \cdot b}\) and simplify using \(i\) where \(i = \sqrt{-1}\).
For the expression \(\frac{\sqrt{-4}}{\sqrt{2}}\), simplify the square roots separately, convert the negative square root to involve \(i\), and then simplify the fraction.
To simplify \(\sqrt{-14} \cdot \sqrt{-2}\), we first recognize that the square root of a negative number involves the imaginary unit \(i\), where \(i = \sqrt{-1}\). Thus, we can express the square roots as:
\[
\sqrt{-14} = \sqrt{14} \cdot i \quad \text{and} \quad \sqrt{-2} = \sqrt{2} \cdot i
\]
Using the property \(\sqrt{a} \cdot \sqrt{b} = \sqrt{a \cdot b}\), we have:
\[
\sqrt{-14} \cdot \sqrt{-2} = (\sqrt{14} \cdot i) \cdot (\sqrt{2} \cdot i) = \sqrt{28} \cdot i^2
\]
Since \(i^2 = -1\), this simplifies to:
\[
\sqrt{28} \cdot (-1) = -\sqrt{28}
\]
Simplifying \(\sqrt{28}\), we get:
\[
\sqrt{28} = \sqrt{4 \cdot 7} = 2\sqrt{7}
\]
Thus, the expression simplifies to:
\[
-2\sqrt{7} \approx -5.2915
\]
For the expression \(\frac{\sqrt{-4}}{\sqrt{2}}\), we first simplify the square roots:
\[
\sqrt{-4} = \sqrt{4} \cdot i = 2i
\]
\[
\sqrt{2} = \sqrt{2}
\]
Thus, the expression becomes:
\[
\frac{2i}{\sqrt{2}} = \frac{2}{\sqrt{2}} \cdot i
\]
Simplifying \(\frac{2}{\sqrt{2}}\), we have:
\[
\frac{2}{\sqrt{2}} = \sqrt{2}
\]
Therefore, the expression simplifies to:
\[
\sqrt{2} \cdot i \approx 1.4142i
\]
\[
\begin{array}{c}
-2\sqrt{7} \\
\sqrt{2} \cdot i
\end{array}
\]