WHY WE ARE INCLUDIND THAT DENOMINATOR SHOULD NEVER BE ZERO,IF THERE IS ANY REASON THEN WILL ANY PROVE IT?

Because anything/0 is not defined in mathematics.It is the fundamental of Mathematics.It is according to the theory of numbers.anthing/0 is infinity and infinity is not a number rather its a behavior,so u cant figure out infinity on paper..For more information u can go through The Theory of Numbers.

DEAR RAHUL,

             denominator should never be zero because x/0 form fractions are not defined. please approve my ans if you like it.