Of course.
if n is known, say n=4 then,
1+1/2+1/3+1/4 =2.08333...
If you are asking in terms of a Limit to the series then
Lim [1+1/2+1/3+...+1/n] ~ 2 1/2
2007-01-04 19:10:50
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answer #1
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answered by stan w 3
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The harmonic series diverges. So if n = ∞. The sum = ∞.
This can be seen this way.
1 + 1/2 + (1/3 + 1/4) + (1/5 + 1/6 + 1/7 + 1/8) ...
< 1 + 1/2 + (1/4 + 1/4) +(1/8 + 1/8 +1/8 +1/8) ...
= 1 + 1/2 + 1/2 + 1/2 ...= ∞
Because you are adding an infinite number of 1/2's together.
2007-01-04 19:39:56
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answer #2
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answered by Northstar 7
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Trace function y(x)=1/x between x1=j and x2=j+1; the area of trapezium between y(x) and x-axis s(j) = integral{for x=j until j+1} of dx/x = ln(x){for x=j until j+1} = ln(j+1) –ln(j); meanwhile a trapezium s(j) < rectangle 1/j;
Thus H(n) = Sum{for j=1 until n} of 1/j > Sum{for j=1 until n} of {ln(j+1) -ln(j)} = (ln2-ln1) +(ln3-ln2) +(ln4-ln3) +(ln5-ln4) +++ (ln(n+1)-ln(n)) =ln(n+1) = or = integral{for x=1 until n+1} of dx/x;
If n - -> infinity then ln(n+1) - - > infinity; so H(n) - - > infinity for sure!
This was the proof that harmonic series does not converge.
Now a formula: suppose you know exactly E(5) = 1+1/2 +1/3 +1/4 +1/5 =2.283333; then H(10) = E(5) +ln(10.5/5.5) = 2.92996 will be a good approximation for exact E(10) = 2.928968;
Approximate H(20) = E(5) +ln(20.5/5.5) = 3.59901, while exact H(20) = 3.59774;
Or a better approximation H(20) = E(10) +ln(20.5/10.5) = 3.598018;
I’d recommend H(n) =E(10) +ln((n+0.5)/10.50292) for better coincidence.
2007-01-05 07:41:37
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answer #3
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answered by Anonymous
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There is no nifty formula to calculate it exactly. To calculate it exactly will take some brute work.
2007-01-04 19:25:17
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answer #4
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answered by its_ramzi 2
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well the denominator
would be n!
and the numerator
wud be something like:
n!+n!/2+n!/3+......+1
i think
2007-01-04 19:15:28
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answer #5
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answered by Maths Rocks 4
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NO POSSIBLE ANSWER.SORRY
2007-01-04 18:58:02
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answer #6
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answered by freddelorme35 3
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