# How do you find the slope of the secant lines of f(x) = sqrtx at P(4,2)?

Mar 16, 2017

See below

#### Explanation:

$\frac{f \left(4 + h\right) - f \left(4\right)}{\left(4 + h\right) - \left(4\right)} = \frac{\sqrt{4 + h} - 2}{h}$

$= \frac{\left(\sqrt{4 + h} - 2\right)}{h} \frac{\left(\sqrt{4 + h} + 2\right)}{\left(\sqrt{4 + h} + 2\right)}$

 = ((4+h)-4)/(h(sqrt(4+h)+2)

 = 1/((sqrt(4+h)+2)