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(mander.xyz)
A place for majestic STEMLORD peacocking, as well as memes about the realities of working in a lab.

Rules
This is a science community. We use the Dawkins definition of meme.
I had a student tasked with summing a finite geometric sequence with |r|>1, let's say 1+2+4+8+16. He had apparently forgotten the formula for that, but knew the formula for the infinite series a/(1-r). Good enough he thinks, and sums 1+2+4+... = -1, then subtracts off the excess terms 32+64+128+... = -32, and gets the correct answer of 31.