1. ## Derivative

find the equation of the tangent line to $f(x) = x+\sqrt{x}$ at (4,6)

$\frac{(x+\sqrt{x})-(4+\sqrt{4})}{x-4}$

= $\frac{x-4+\sqrt{x}-\sqrt{4}}{x-4}$

why am I havin so much trouble getting that denominator out of there

2. $\frac{(x + \sqrt{x}) - (4 + \sqrt{4})}{x-4} =$

$\frac{x + \sqrt{x} - 6}{x-4} =$

$\frac{(\sqrt{x} + 3)(\sqrt{x} - 2)}{(\sqrt{x} + 2)(\sqrt{x} - 2)} =$

$\frac{\sqrt{x} + 3}{\sqrt{x} + 2}$

now take the limit