Solution (source code)

= Solution

The original PDF specifies $x\to a$. The quotient is the <difference quotient> for the <function> $f(x)=x^x=e^{x\ln x}$ at the positive <point> $a$. The <chain rule> gives $f'(x)=x^x(\ln x+1)$, so
$$
\boxed{\lim_{x\to a}\frac{x^x-a^a}{x-a}=a^a(1+\ln a),\qquad a>0.}
$$