Science:Math Exam Resources/Courses/MATH110/April 2016/Question 05 (f)/Solution 2
(Alternative solution) From the solution 1, we know that the only critical point is . Now let’s calculate the second derivative
At , , so by the second derivative test in the Hint 2, it attains local maximum at this point.
In all, it has no local minimum, but has a local maximum at and .