Question

Find which of the following algebraic expression is a polynomial.

(i) $3x^2-5x$
(ii) $x+\frac{1}{x}$
(iii) $\sqrt{y}-8$

Answer 1

(i) $3x^2-5x=3x^2-5x^1$
It is a polynomial.
(ii) $x+\frac{1}{x}=x^1+x^{-1}$
It is not a polynomial
(iii) $\sqrt{y}-8=y^{1/2}-8$

Since, the power of the first term
($\sqrt{y})$ is 1/2, which is not a whole number.
Therefore it is not a polynomial.