7.7 Practice, Problem 3
Problem 3
Determine the intervals in which the graph is concave upward or downward.
Solution
For concave upward f″> 0
Since is always greater than zero.
Therefore,
> 0 , x < – 5 or x > 5
f (x) is concave upward on (– ∞, – 5) and (5, ∞) and concave downward on (– 5, 5).