What is the value of the Cesaro's sum of ? If you think that the value of the sum is infinite, enter .
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Let the equation equate to a variable S .
1 − 1 + 1 − 1 + 1 − 1 + . . . = S
From here, we can bracket the equations differently:
( 1 − 1 ) + ( 1 − 1 ) + ( 1 − 1 ) + . . . = S
1 + ( − 1 + 1 ) + ( − 1 + 1 ) + ( − 1 + 1 ) + . . . = S
We can then sum the equations, solving every sub-equation within the brackets:
1 + 0 + 0 + 0 + 0 + 0 + 0 + . . . = 2 S
S = 2 1
This answer, however, may be wrong as by bracketing the equations differently, we can derive 0 = 1 . I remember reading somewhere you take partial sums of the equation, then average between the answers, which leads to the answer being 2 1 due to the partial equations not converge on a single value but rather jumping between 0 and 1 constantly.