https://leangsimschoolboy.files.wor dpress.com/2013/09/stude

>>9151310
the latter part meaning how [math] \sum_{n=1}^{\infty} \frac{1}{n} [/math] is divergent?

see if you can find any way to show that the sum adds up the same number infinitely many times.
i'll give you a hint:
[math] \frac{1}{3} + \frac{1}{4} > \frac{1}{4} + \frac{1}{4}[/math]

>>9151325

Thanks but by latter part I meant the explanation in the pdf immediately below what's shown in the picture. the r>=2 part

>>9151343
look at this and see if you can figure it out
[math] \frac{(n-r)!}{(n)!}, r \ge 2 \implies \frac{(n-r)!}{(n)!} \ge \frac{(n-2)!}{(n)!} = \frac{(n-2)!}{(n)(n-1)(n-2)!} = \frac{1}{(n-2)!} [/math]

>>9151372
woops i botched that final expression.
you should be able to see what it should be