To divide the polynomial \( x^3 - a^3 \) by \( x - a \), we can use polynomial long division or recognize that \( x^3 - a^3 \) is a difference of cubes, which can be factored using the formula:
\[ x^3 - a^3 = (x - a)(x^2 + ax + a^2) \]
Thus, the polynomial identity established by dividing \( x^3 - a^3 \) by \( x - a \) is:
\[ x^3 - a^3 = (x - a)(x^2 + ax + a^2) \]
The correct response from the options you provided is:
\( x^3 - a^3 = (x - a)(x^2 + ax + a^2) \).