Square roots are always causing trouble for me - especially finding the limit of a function when it's in the indeterminate form.
I got this far, but I don't know what to do next or even if it's right. Trying to go any further gives me my original problem.
This is the initial problem $ \lim_{x\to5}\frac{\sqrt{ x^2+5}-\sqrt{30}}{(x-5)} $
This is where I've gotten $ \lim_{x\to5}\frac{\sqrt{x^2+5}-\sqrt{30}}{(x-5)} * \frac{\sqrt{x^2+5}+\sqrt{30}}{\sqrt{x^2+5}+\sqrt{30}} = \frac{x^2+5-30}{(x-5)\left(\sqrt{x^2+5}+\sqrt{30}\right)} $