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4 Series
9730#9737 SIBLINGS CHILDREN 9737
 
411 Geometric Series
9730#9729 SIBLINGS CHILDREN 9729
 
411 Geometric Series
ᐥThe geometric series 「a·x˄r Σr=0,∞」 = a + a·x + a·x² + ... (a≠0) converges if and only if |x|<1. Moreover, its sum is then a/(1−r).ᐥ Partial sum, (1−x)·「a·x˄r Σr=0,n−1」 = 「a·x˄r Σr=0,n−1」 − 「a·x˄(r+1) Σr=0,n−1」 = 「a·x˄r Σr=0,n−1」 ┆「a·x˄(r+1) Σr=0,n−1 ...
9730#9731 SIBLINGS CHILDREN COMMENT 9731
 
415 p-series
The p-series 「1/n˄p Σn=1,∞」 converges if p>1 and diverges if p≤1.
9730#473 SIBLINGS CHILDREN 473
 
415 Harmonic series
「1/n Σn=1,∞」 diverges
9730#3652 SIBLINGS CHILDREN 3652
 
415 「1/n² Σn=1,∞」
「1/n² Σn=1,∞」 converges
9730#24853 SIBLINGS CHILDREN 24853
 
421 First comparison test
ᐥIf 0 ≤ a⸤n⸥ ≤ b⸤n⸥ for all n∈ℕ then (a) 「b⸤i⸥ Σi=1,∞」 converges ⇒ 「a⸤i⸥ Σi=1,∞」 converges (b) 「a⸤i⸥ Σi=1,∞」 diverges ⇒ 「b⸤i⸥ Σi=1,∞」 divergesᐥ Proof of (a) ┆0 ≤ a⸤n⸥┆ 「a⸤i⸥ Σi=1,n」 is increasing. 「a⸤i⸥ Σi=1,n」 ┆a⸤n⸥ ≤ b⸤n⸥┆ ≤ 「b⸤i⸥ Σi=1,n」 ┆0 ≤ b⸤n⸥┆ ...
9730#5038 SIBLINGS CHILDREN 5038
 
422 Second comparison test
ᐥLet 「a⸤n⸥ Σn=1,∞」 and 「b⸤n⸥ Σn=1,∞」 be positive-term series such that 「a⸤n⸥/b⸤n⸥ Σn=1,∞」 = L ≠ 0. Then 「a⸤n⸥ Σn=1,∞」 converges if and only if 「b⸤n⸥ Σn=1,∞」 converges.ᐥ
9730#9785 SIBLINGS CHILDREN 9785
 
A first look at series
9730#9912 SIBLINGS CHILDREN 9912
 
Power Series
9730#9780 SIBLINGS CHILDREN 9780
 
Proverbs and Quotes in English
Short sentences and easy words.
 
◌◌◌ Series
A series is, roughly speaking, a description of the operation of adding infinitely many quantities, one after the other, to a given starting quantity.
9730#5170 SIBLINGS CHILDREN 5170

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