# How do you find the slope of the secant lines of #f(x) = 7x^2# at #(4, f(4))# and #(4+h, f(4+h))#?

##### 1 Answer

Jun 5, 2016

#### Explanation:

Find the points at

#f(4)=7(4)^2=7(16)=112#

#f(4+h)=7(4+h)^2=7(16+8h+h^2)=112+56h+7h^2#

The slope of the secant line is the slope of the line connecting the points

The slope is

#m=((112+56h+7h^2)-112)/((4+h)-4)=(56h+7h^2)/h=56+7h#