To determine which polynomial identity results from dividing \( x^2 - a^2 \) by \( x - a \), we can use the fact that \( x^2 - a^2 \) can be factored using the difference of squares formula:
\[ x^2 - a^2 = (x - a)(x + a) \]
When you divide \( x^2 - a^2 \) by \( x - a \), you effectively have:
\[ \frac{x^2 - a^2}{x - a} = x + a \]
This shows that \( x^2 - a^2 \) can be expressed as \( (x - a)(x + a) \).
Hence, the correct option is:
Option #1: \( x^2 - a^2 = (x - a)(x + a) \).