To find which polynomial identity results from dividing \( x^3 + a^3 \) by \( x + a \), we can use the factorization of the sum of cubes. The sum of cubes can be factored as follows:
\[ x^3 + a^3 = (x + a)(x^2 - ax + a^2) \]
From this factorization, it is clear that when we divide \( x^3 + a^3 \) by \( x + a \), the quotient will be \( x^2 - ax + a^2 \).
Therefore, the correct option is:
Option 2: \( x^2 - ax + a^2 \)