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MAT 1236 Calculus III. Section 11.6 Absolute Convergence and the Ratio and Root Tests. http://myhome.spu.edu/lauw. HW 11.4 #13 solutions. See Method I Bonus points for an alternative solution with “significant” difference. No Class Tomorrow. Take the time to review for the final. HW.
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MAT 1236Calculus III Section 11.6 Absolute Convergence and the Ratio and Root Tests http://myhome.spu.edu/lauw
HW 11.4 #13 solutions • See Method I • Bonus points for an alternative solution with “significant” difference.
No Class Tomorrow • Take the time to review for the final
HW • WebAssign 11.6
Preview • We want tests that work for general series • DefineAbsolute Convergence • DefineConditional Convergence • Abs. ConvergentimpliesConvergent • Ratio/Root Tests(No requirement on the sign of the general terms of the series)
Definition is absolutely convergent if is convergent The point: Absolute convergence may be easier to show, because …
Theorem If is absolutely convergent then is convergent
Theorem If is absolutely convergent thenis convergent OR equivalently If is convergent then is convergent
Theorem If is absolutely convergent then is convergent OR equivalently If is convergent then is convergent The point: To show a series is convergent, it suffices to show that it is abs. convergent.
Theorem If is absolutely convergent then is convergent OR equivalently If is convergent then is convergent WHY?
Converges. Why? Example 1(More or Less…) Converges
Example 1 The phrase used here is long, we are going to replace it by
T or F? If is not absolutely convergent then is divergent.
Definition is conditionally convergent if is convergent but not abs. convergent
Definition is conditionally convergent if is convergent but not abs. convergent Convergent Series
Expectations Important Details: • Write down the general terms • Take the limit of the abs. value of the ratio of the general terms • Clearly mark the criterion • Make the conclusion by using the Ratio Test
Example 3 Note that: because
Example 5 • No conclusion from the Ratio Test • If Ratio Test fails, then Root Test will fail too
Example 5 Plan: Use limit comparison testto show that the series is absolutely convergent. That is, we are going to show that the series is convergent. Then is (abs.) convergent
Question Why not use the comparison test directly on the series?