Answer
a. $x=3$
b. $x=4$
Work Step by Step
a. The original function is $ f(x)=x^2-6x+5$ therefore $ f'(x)=2x-6 $
Set that function equal to 0 to find all of the values of $x$ where the slope of the curve is 0:
$ 2x-6=0 $
$ 2x=6 $
$ x=3 $
b. The equation found in part a still applies so you set it equal to 2:
$ 2x-6=2 $
$ 2x=8 $
$ x=4$
