Please Help! sigma limit see equation in note below
\[\lim_{n \rightarrow \infty} \frac{ 1 }{ n} [(\frac{ i }{ n })^3 +1] \]
sorry should have put sigma with i=1 on bottom and n on top
\[\lim_{n \rightarrow \infty} \sum_{I=1}^{n} \frac{ 1 }{ n} [(\frac{ i }{ n })^3 +1] \]
\[\lim_{n \rightarrow \infty} \sum_{i=1}^{n} (i/n)^{3} + 1\]
Okay I got the question....
I am way lost on this
\[1/n [ i ^{3}/n ^{3} + 1] = 1/n [ (i ^{3} + n^{3}) / n^{3} ] = 1/n^{4} [ i^{3} + n^{3} ] \] Now apply sigma...n is a constant, so bring 1/n^4 out of sigma
\[\sum_{i=1}^{n}i^{3} + \sum_{i=1}^{n}n^{3} \] \[= n^{2}(n+1)^{2} / 4 + (n \times n^{3})\] \[= (5n^{4} + 2n^{3} + n^{2}) / 4 \]
\[\lim_{n \rightarrow \infty} (5n^{4} + 2n^{3} + n^{2}) / 4n^{4}\] \[= \lim_{n \rightarrow \infty} n^{4}(5 + 2/n + 1/n^{2}) / 4n^{4}\] \[= \lim_{n \rightarrow \infty} 5/4 + 2/4n + 1/4n^{2}\] \[= 5/4 + 0 + 0 = 5/4\]
Oh great!! I spent a lot of time solving and typing this just to see that you are offline..! That is satisfying
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