Calculus

Lesson 53

Ratio and Root Tests

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                        These are the last 2!

 

                        Ratio Test:

 

                        if all ,  converges absolutely if .

                        Test fails if

 

                         diverges if

 

 

 

 

                        Root Test:

 

                        if all ,  converges absolutely if  .

 

                        Test fails if .

 

                         diverges if .

 

                

                                                                                   

 

                                                                                               

 

Examples:                  

 

                                                                                               

 

                                   

 

 

 

            Methods:

 

            1)  Test nth term - if not zero, the series diverges.

 

            2)  Is it geometric, p-series, telescoping, or alternating?  If so, write down test result.

 

            3)  Can integral, root, or ratio test be applied?  If so, test!  If test fails or if you can't

                        tell, try another one!

 

            4)  Can the series be compared to another?

 

 

                                    

 

 

 

            More Examples:

                          

 

 

 

                                   

                               

On to Lesson 54 - Taylor Polynomials

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