(1) For an algebraic expression to be a polynomial, the power of the variables must always be a whole number. The expression
1x+x2 can also be written as
x−1+x2
In the above expression, the power of the variable x is -1, which is not a whole number.
Hence, it is not a polynomial.
(2) For an algebraic expression to be a polynomial, the power of the variables must always be a whole number. The expression 2x
2 -
3√x+1. can also be written as 2x
2 -
3x0.5+1.
In the above expression, the power of the variable x is 0.5, which is not a whole number.
Hence, it is not a polynomial.
(3) The expression
x3+5 can be written as
(13)x+5 here the power of x is a whole number
Hence, it is a polynomial .