Back in the day, in my alma mater, we used to have mandatory reserve officers training (one of the reasons why socialism sucks noodle). The lecturers were the dumb-ass officers who couldn’t be kept any longer in the active military forces (among active military dumb-asses).
At some point one of these imbeciles was blabbing about artillery calculations and in the course of “solving” an equation he came to the conclusion that
or some such. One of the math. department’s students raised his hand and expressed his concern
“Comrade major, we – at math. department – actually learned that
Are you sure that your calculations are correct?”
Dumb-ass major (perhaps it was a dumb-ass Lt.-Colonel) looked back, paused for a moment and said “In the time of war cos(x) was reaching 4, but rarely…”