Science:Math Exam Resources/Courses/MATH110/April 2016/Question 05 (h)/Hint 1

Recall that

(1) ${\textstyle f}$ is concave up (convex) on the intervals where ${\textstyle f''(x)>0}$;

(2) ${\textstyle f}$ is concave down on the intervals where ${\textstyle f''(x)<0}$;