Math 121

 

Section 3.2

 

Extrema Points

 

 

Absolute Minimum                                              Absolute Maximum

 

 

 

 

 

 

 

Relative Minimum and Relative Maximum

 

 

                                                                                                           

Inflection Point

 

Types of Critical Points

 

1)      Relative Maximum

2)      Relative Minimum

3)      Absolute Maximum

4)      Absolute Minimum

 

Testing for Extrema Points

 

Find all an extrema points of the function.

 

1)

 

 

 

Interval

 

Test Value

 

x = -1

x = 1

Sign of

 

Negative

Positive

Conclusion

 

Decreasing

Increasing

 

The function is increasing when x is less than -1 and increasing when x is greater than -1.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2) Find all extrema points of the function.

 

 

Interval

 

Test Value

 

x = -1

x = 1

Sign of

 

Positive

Positive

Conclusion

 

Increasing

Increasing

 

 

The function is increasing when x is less than zero and greater than zero, so the function has an inflection point at x = 0.   (See graph above)

 

 

 

 

 

 

 

3)  Find all extrema points of the function.

 

 

 

 

Interval

 

Test Value

 

x = -1

x =

x = 2

Sign of

 

Positive

Negative

Positive

Conclusion

 

Increasing

Decreasing

Increasing

 

 

The function has a relative maximum at x = 0 and a relative minimum at x = 1

(See diagram above)

 

4)

 

 

 

Interval

 

Test Value

 

x = -1

x = 1

Sign of

 

Positive

Negative

 

Conclusion

 

Increasing

Decreasing

 

The function has an absolute maximum at x = 0

See Graph