Calculus
Lesson
15 Concavity
Back to Dr. Nandor's Calculus Notes Page
Back to Dr. Nandor's Calculus Page
Concave up if is
increasing.
Concave down if
is
decreasing.
Concavity changes at points of inflection!!!!
![]() |
|||
![]() |
|||
Since rate of change of is
,
indicates that
is concave up at
.
indicates that
is concave down at
.
indicates a possible
point of inflection at
.
Note that it doesn always mean that there is a point of inflections.
Example:
We must use a sign chart to make sure that changes sign.
If does not
change sign, then
is
not a point of inflection.
For each of f, g, and h, identify all critical points and all points of inflection.
Same Examples as last lesson:
Note:
never equals zero, so
there are no points of inflection!
Also:
Test to see if they
are points of inflection!
If , then the test is
inconclusive - you can always use the
first derivative test!
Example: