Trouble finding the derivative of $\frac{4}{\sqrt{1-x}}$ I've been trying to figure out how to differentiate this expression, apparently I don't know my differentiation rules as much as I thought. I've been trying to use Wolfram Alpha as a guide but I'm at a loss.
I need to differentiate $$\frac{4}{\sqrt{1-x}}$$
I first pull out the four so the problem becomes: $$4 * \frac{1}{\sqrt{1-x}}$$
I'm not sure what to do next, do I use the quotient rule? Wolfram alpha is giving me some crazy answers, I would appreciate it if someone could walk me through this step by step. Thanks.

A general hint: $\sqrt{f(x)} = f(x)^{\frac{1}{2}}$ and behave it like $x^r$.
