Question

Which of the following is not a polynomial?

(a) x^2+5x+10

(b) √x+2x+4

(c) x^10+10x

(d) 5x+4

This question was posed to me in an interview for internship.

This is a very interesting question from Geometrical Meaning of Zeros of Polynomial topic in section Polynomials of Mathematics – Class 10

Answer 1

Right option is (b) √x+2x+4

To elaborate: An expression in the form of (x)=a0+a1x+a2x^2+…+anx^n, where an≠0, is called a polynomial where a1, a2 … an are real numbers and each power of x is a non-negative integer.

In case of √x+2x+4, the power of x is not an integer.

Therefore it is not a polynomial.