EXAMPLE Find the extreme values of f(x)= 2x3 − 15x2 + 24x + 7 on [0, 6].

Solution The extreme values occur at critical points or endpoints, so we can break up the problem neatly into two steps.

Step 1. Find the critical points.

The function f(x) is differentiable, so we find the critical points by solving




The critical points are c = 1 and 4.


Step 2. Calculate the y-value at the critical points and endpoints and compare.




The maximum of f(x) on [0, 6] is the largest of the values in this table, namely f(6) = 43
           (Figure 9). Similarly, the minimum is f(4) = − 9.

Extreme values

  • 1.
    EXAMPLE Find theextreme values of f(x)= 2x3 − 15x2 + 24x + 7 on [0, 6]. Solution The extreme values occur at critical points or endpoints, so we can break up the problem neatly into two steps. Step 1. Find the critical points. The function f(x) is differentiable, so we find the critical points by solving The critical points are c = 1 and 4. Step 2. Calculate the y-value at the critical points and endpoints and compare. The maximum of f(x) on [0, 6] is the largest of the values in this table, namely f(6) = 43 (Figure 9). Similarly, the minimum is f(4) = − 9.