Given, \(\lim\limits_{\text x \to a}\cfrac{a\,sin\,\text x-\text x\,sin\,a}{a\text x^2-\text x a^2} \)
Let t = x - a
Then, as x→a, t→0
Hence, \(\lim\limits_{\text x \to a}\cfrac{a\,sin\,\text x-\text x\,sin\,a}{a\text x^2-\text x a^2} \) = \(\cfrac{a\,cos\,a-sin\,a}{a^2}\)