They just love it in French engineering schools. They bring it on the day of the test, if you make an odd number of sign error you completely miss the trick, i

They just love it in French engineering schools. They bring it on the day of the test, if you make an odd number of sign error you completely miss the trick, if you check your results for general coherency you'll never believe they are rotating in the same direction and you'll loose quite some time checking your stuff.