Question

Can the numerator equal to zero in a rational expression?

Answer 1

Yes, it can. And that will make the fraction equal 0.

Answer 2

Though, it can't equal 0 in the denominator.

Answer 3

Unless, of course, you mean to signify infinity :).

Answer 4

Yes, exactly.

Answer 5

The denominator must never have 0 in it :)

Answer 6

Well, say the denominator is 2+x, where x=0, the expression is perfectly OK. I'd say that the denominator should never reduce to zero.