



 
Hi Carla, The derivative of $f(x)$ is the limit, as $h$ approaches zero of the difference quotient \[\frac{f(x + h)  f(x)}{h}.\] For your function this difference quotient is \[\frac{(x + h + 1)^{1/2}  (x + 1)^{1/2}}{h}.\] If you multiply the numerator and denominator by $(x + h + 1)^{1/2} + (x + 1)^{1/2}$ and simplify you will arrive at an expression that can be evaluated as $h$ approaches zero. I hope this helps,  


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