To find the cube root of 81, we can express it using the notation for cube roots:
\[ \sqrt[3]{81} \]
Calculating the cube root of 81 gives us a numerical value. Since 81 can be rewritten as \(3^4\), we have:
\[ \sqrt[3]{81} = \sqrt[3]{3^4} = 3^{4/3} = 3^{1 + 1/3} = 3 \cdot 3^{1/3} \]
Thus, the cube root of 81 is approximately \(4.326\). However, none of the provided responses accurately reflect this calculation.
From the choices given, the closest numerical approximation consistent with the principle is not within the options listed (27, \( \sqrt[3]{81} \), 9, -9).
The answer is:
\[ \sqrt[3]{81} \approx 4.326 \]
Since this value is not directly in the responses, it suggests there might be an error in the options or they were not intended to directly calculate the value. The actual cube root of 81 is not provided correctly. Thus, among your options, the valid descriptions do not equate to the correct answer which is approximately \(4.326\).
Correct answer is \( \sqrt[3]{81} \).