Question

Use your calculator to select the best answer below:

Answer 1

Answer:

$-2\sqrt{a}$

Step-by-step explanation:

$\lim_{x \to a} \frac{a-x}{\sqrt{x} -\sqrt{a} } \\ =-\lim_{x \to a} \frac{x-a}{\sqrt{x} -\sqrt{a} } \\=-\lim_{x \to a} \frac{(\sqrt{x} -\sqrt{a})(\sqrt{x} +\sqrt{a})}{\sqrt{x} -\sqrt{a} } \\=- \lim_{x \to a} \sqrt{x} +\sqrt{a}\\=-2\sqrt{a}$