I borrowed $50 from mum and $50 from dad to buy a bag costing $97. After the purchase, I had $3 left. I returned $1 to dad and $1 to mum, and reserved $1 for myself. I now owe $49+$49=$98 plus the $1 I reserved for myself, which is $99. Where is the missing $1?
Does an integral exist for log (1+x/1-x) from -1 to 1?