Thus. Then. This tells us that the absolute
valueof the erroror remainderis less than 0.13.
Absoluteand ConditionalConvergence
Thereare othertypesof convergencefor infiniteseries:absoluteconvergenceandconditionalconver-
gence.
AbsoluteConvergenceLet be an infiniteseries.Thenthe
seriesisabsolutelyconvergentif converges.
The infiniteseries is the seriesmadeby takingthe ab-
solutevaluesof the termsof the series
The convergenceof the seriesof absolutevaluestells us somethingaboutthe convergenceof the series.
Theorem If , then
also converges.
This tells us that if you can showabsoluteconvergence,then the seriesconverges.
If the seriesof absolutevaluediverges,we cannotconcludeanythingaboutthe series.
Example 3
Determineif the series convergesabsolutely.
Solution
We find the seriesof absolutevalues: , whichbehaveslike the series
. This is ap-serieswithp= 4. The series convergesabsolutelyand henceconverges.
Example 4