### Home > CALC > Chapter 10 > Lesson 10.1.8 > Problem10-79

10-79.

Find the equation of a line such that $f^\prime(3) = 2$ and $f(3) = 5$. Now find the equation of the normal line at $x = 3$.

This is a line with a slope of $2$ passing through the point $(3, 5)$.
"Normal" means perpendicular. The slope of the normal line is  $–1/2$.