### Home > APCALC > Chapter 8 > Lesson 8.2.2 > Problem8-85

8-85.

Multiple Choice: $f(x) = e^{-x} - x^3 + 3x^2 - 10x$ changes concavity at $x =$

1. $-2.03$

1. $-1.54$

1.  $0.32$

1.  $1.06$

1.  $2.35$

Concavity change might (or might not) happen where $f^{\prime\prime}(x) = 0$. Remember, you must confirm that concavity CHANGES at that candidate by detecting a sign change in the second derivative before and after the candidate, or by confirming that third derivative at the candidate is not equal to $0$.