the end of a drop or bottom is not something you can calculate with some formula! you can analyze the market and come up with an speculation but that is about it. read speculation board and some stuff on technical analysis and look at sites like tradingview.com to get how things work.
If the price of bitcoin is lower than the mining cost of miners, then the miners are greatly reduced.
yes but then the cost of mining will lower and it again becomes profitable.
BTC will be attacked by 51%.
price has to drop A LOT more than a small drop and A LOT of miners have to go away for a 51% to become possible!
It is not accepted for all Bitcoin holders. Especially whales. Calculating the mining cost of a miner may approximate the base price of BTC in the near future.
no it is not. price is (to put simply) determined with supply and demand. the cost does not matter at all.