## Precalculus (6th Edition) Blitzer

$9$ and $y=9x-2$
Now, $m_{\tan}=\lim_\limits{ h\to 0} \dfrac{f(1+h)-f(1)}{h}$ or, $=\lim_\limits{ h\to 0} \dfrac{2(1+h)^2+(5+h)-2(1)^2-(5)(1)}{h}$ or, $=\lim_\limits{ h\to 0} \dfrac{2h^2+9h}{h}$ or, $=9$ The equation of a line is: $y=mx+c$ Now, $y-7=9(x-1) \implies y=9x-2$