My head-canon with dividing by zero is that 1/0 = undefined and 1/-0 = -undefined, and that's where I leave it because anything less funny than that seems like an impractical answer.

I am fine if isFinite(1/0) returns false.

0 / 0 = Any number

non-zero / 0 = No number

0/0 might be a specific number. You have to go and use l'hopitals rule to work out what it might be.