Answer
Shown below.
Work Step by Step
Suppose E and F are independent. Then
\begin{align*} P(\bar{E} \cap \bar{F}) &= 1 - P(E \cup F) \\
&= 1 - [P(E) + P(F) - P(E \cap F)] \\
&= 1 - P(E) - P(F) - P(E)P(F) \\
&= (1 - P(E))(1 - P(F)) \\
&= P(\bar{E})P(\bar{F})
\end{align*}