Given:

$\displaystyle \sqrt{x+2}$ at the point $\displaystyle (7,3)$

I need to use the limit definition of :

$\displaystyle m= \lim_{\Delta x\rightarrow 0} \frac{f(x+\Delta x)- f(x)}{\Delta x}$

to find an equation of the tangent line to the graph of $\displaystyle f$ at the given point (above).