Rational Function: It is in the form of a fraction, like a0+a1x+a2x2+a3x3…+anxnb0+b1x+b2x2+b3x3…+bnxn where a0, a1, a2, a3, an and b0, b1, b2, b3…bn are all constants. The function is defined for every x is an element of real number and the denominator should not be equal to zero.