# How do you find the slope of the secant lines of f(x)=6.1x^2-9.1x through the points: x=8 and x=16?

Apr 25, 2016

137.3

#### Explanation:

$f \left(8\right) = \left(6.1\right) \left(64\right) - \left(9.1\right) \left(8\right) = 317.6$. This point is (8, 317.6).

$f \left(16\right) = \left(6.1\right) \left(256\right) - \left(9.1\right) \left(16\right) = 1416$. This point is (16, 1416).

The slope of the secant line joining these two points
=$\frac{1416 - 317.6}{16 - 8} = 137.3$