It is very useful in engineering to do things that are mathematically impossible, by simply ignoring or rejecting the last 1%. Sometimes that's unacceptable, b

It is very useful in engineering to do things that are mathematically impossible, by simply ignoring or rejecting the last 1%. Sometimes that's unacceptable, because you really do care about 100% of cases. When it isn't, you get really cool "impossible" tools out of it :)