Chapter 4 - Applications of the Derivative - 4.2 Extreme Values - Exercises - Page 180: 4

None.

Let x be the critical point. This implies f'(x)=0 or f is not differentiable. The function f which is a linear function is differentiable at every point. Also f'(x)= $\frac{d}{dx}(7x-2)= 7$ ⇒ f'(x)≠0. Thus f(x)=7x-2 has no critical points.