To simplify the expression \((a^{-1} \cdot a^{-2})^{-3}\) and represent it as a power of \(a\), we can follow these steps:
- First, use the property of exponents that states \(a^m \cdot a^n = a^{m+n}\):
\[ a^{-1} \cdot a^{-2} = a^{-1 + (-2)} = a^{-3} \]
- Now, we can substitute this back into the expression:
\[ (a^{-3})^{-3} \]
- Next, apply the power of a power property, which states \((a^m)^n = a^{m \cdot n}\):
\[ (a^{-3})^{-3} = a^{-3 \cdot (-3)} = a^{9} \]
Thus, the expression \((a^{-1} \cdot a^{-2})^{-3}\) can be represented as:
\[ \boxed{a^9} \]