CPM Homework Help : CALC Problem 8-129

Multiple Choice: Given f(x) = −4x² + 7x, then f is concave up for … Homework Help ✎
1. x ≠ 0
2. no values of x
3. x < 0
4. x < 0 or x >
5. 0 < x <

Hint:

Recall that candidates for points of inflection occur where the 2nd-derivative equals zero AND where the 2nd-derivative does not exist.

Steps:

After you identify where f ''(x) = 0 and where f ''(x) = DNE, check the regions before, after and between those candidates: if f ''(x) > 0, then f(x) is concave up.