$\begingroup$Let $y=\ln x$. Find the slope of the secant line between $P=(5, \ln5)$ and $Q=(9, \ln9)$.
Should I just replace $\ln x$ with any of those two points? Ex: $y=\ln9$ or $y=\ln5$??
Please Help!!
$\endgroup$21 Answer
$\begingroup$Finding the slope of the secant line between two points is just a fancy way of being asked to apply the usual slope formula of rise over run to two points. Hence, we obtain: $$ \dfrac{\ln 9 - \ln 5}{9 - 5} $$
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