[tex]\bf slope = {{ m}}= \cfrac{rise}{run} \implies
\cfrac{{{ f(x_2)}}-{{ f(x_1)}}}{{{ x_2}}-{{ x_1}}}\impliedby
\begin{array}{llll}
average\ rate\\
of\ change
\end{array}\\\\
-------------------------------[/tex]
[tex]\bf f(x)= 7sin(x)-1 \qquad
\begin{cases}
x_1=0\\
x_2=\frac{\pi }{2}
\end{cases}\implies \cfrac{f\left( \frac{\pi }{2} \right)-f(0)}{\frac{\pi }{2}-0}
\\\\\\
\cfrac{[7\cdot 1-1]~-~[7\cdot 0-1]}{\frac{\pi }{2}}\implies \cfrac{6-(-1)}{\frac{\pi }{2}}\implies \cfrac{6+1}{\frac{\pi }{2}}\implies \cfrac{7}{\frac{\pi }{2}}\implies \cfrac{14}{\pi }[/tex]