#### seanieg89

##### Well-Known Member

- Joined
- Aug 8, 2006

- Messages
- 2,662

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- HSC
- 2007

**Re: HSC 2016 4U Marathon - Advanced Level**

Written as intended, in step 2 you are only dealing with finite sums and integration is not the only thing you are doing in step 4. I just didn't want to be too explicit/prescriptive about the limiting argument, as methods will vary depending on level of mathematical knowledge.

If you naively allow exchanges of infinite series and integrals, then this calculation gives you zeta(2) quite speedily. If any university students attempt this, I would hope for a little more care.