Question

Which of the following expressions are polynomials?
(i) $x^2+4$
(ii) $4-x^{-1}$
(iii) $2x^2-\frac{2}{x}$

• A. i
• B. i, ii, iii
• C. iii
• D. ii, iii

Answer 1

The correct option is A

i

Polynomials cannot have variables with exponents as negative integers.
Hence, $4-x^{-1}$ and $2x^2-\frac{2}{x}$ are not polynomials as the variable 'x' has (-1) as the exponent.

$x^2+4$ has the variable $x$, the power of the variable is a positive integer 2 , a constant term 4 and the operator '+'.
Hence, $x^2+4$ is a polynomial.