We are given the limit expression:
\[
\lim_{x \to a} \frac{x^n + a^n}{x + a}
\]
Step 1: Evaluate the limit
This is a standard limit problem. As \( x \to a \), the expression simplifies to:
\[
\frac{a^n + a^n}{a + a} = \frac{2a^n}{2a} = \frac{a^n}{a}
\]
Step 2: Differentiate the result
Once we have simplified the expression, we can differentiate it. Since we are differentiating a constant function, the derivative is 0.
Thus, the answer is 0.