The Negative Exponent Rule states that \( a^{-n} = \frac{1}{a^n} \).
To apply this rule to the expression \( 3^{-1/2} \), we rewrite it as follows:
\[ 3^{-1/2} = \frac{1}{3^{1/2}} \]
Since \( 3^{1/2} \) is equivalent to the square root of 3, we can further simplify the expression:
\[ 3^{-1/2} = \frac{1}{\sqrt{3}} \]
Therefore, an equivalent expression to \( 3^{-1/2} \) is:
\[ \frac{1}{\sqrt{3}} \]