Is the following expression polynomials x^(-2) ? If not, mention reason ?

Which of the following expressions is a polynomial?

Which of the following expressions are polynomials? Which are not? Give Reasons. sqrt 3x^2+5y is a polynomial

Which of the following expressions are polynomials? Which are not? Give Reasons. 1/x+1

Which of the following expressions are polynomials? Which are not? Give Reasons. 4x^2+5x-2

Which of the following expressions are polynomials? Which are not? Give Reasons. 2x^2+3/x-5

Which of the following expressions are polynomials? Which are not? Give Reasons. 3xyz is a polynomial

Which of the following expressions are polynomials? Which are not? Give Reasons. 5 is constant polynomial

Which of the following expressions are polynomials? Which are not? Give Reasons. Y^2-8

Which of the following expressions are polynomials? Which are not? Give Reasons. sqrt x is not a polynomial as its exponent is not an integer.

Factorise the following expressions x^(2) - 5x -2 4