Example3:
Let’s examinethe function
- Find the criticalvaluesfor which
or
at
Notethat when
- Applythe First and SecondDerivativeTests to determineextremaand pointsof inflection.
We can note the signsof and in the intervalspartionedby
Key intervals Shapeof graph
Increasing,concavedown
Decreasing,concavedown
Decreasing,concaveup
Increasing,concaveup
Also note that By the SecondDerivativeTest we have a relativemaximumat
or the point
In addition, By the SecondDerivativeTest we havea relativeminimumat or the
point Now we can sketchthe graph.
LessonSummary
- We learnedto identifyintervalswherea functionis concaveupwardor downward.
- We appliedthe First and SecondDerivativeTests to determineconcavityand sketchgraphs.
ReviewQuestions - Find all extremausingthe SecondDerivativeTest.