if $f(x)=4x + 12$, find the slope of the secant line between the values of $x_1=-9$ and $x_2 = 8$.
if $f(x)=4x + 12$, find the slope of the secant line between the values of $x_1=-9$ and $x_2 = 8$.
Answer
Explanation:
Step1: Find $f(x_1)$
Substitute $x_1=-9$ into $f(x)=4x + 12$. $f(x_1)=4\times(-9)+12=-36 + 12=-24$
Step2: Find $f(x_2)$
Substitute $x_2 = 8$ into $f(x)=4x + 12$. $f(x_2)=4\times8+12=32 + 12=44$
Step3: Calculate the slope of the secant line
The slope formula of the secant line between two points $(x_1,f(x_1))$ and $(x_2,f(x_2))$ is $m=\frac{f(x_2)-f(x_1)}{x_2 - x_1}$. $m=\frac{44-(-24)}{8-(-9)}=\frac{44 + 24}{8 + 9}=\frac{68}{17}=4$
Answer:
$4$