NCERT Exemplar Solutions
Class 10 - Mathematics - CHAPTER 4: Quadatric Equation - Exercise 4.2
Question 3

Question. 3

A quadratic equation with integral coefficients has integral roots. Justify.

Answer:

False.

Detailed Answer with Explanation:

Let us check step by step:

  1. A quadratic equation is of the form \(ax^2 + bx + c = 0\), where \(a, b, c\) are numbers and \(a \neq 0\).
  2. "Integral coefficients" means that \(a, b, c\) are whole numbers (positive, negative, or zero).
  3. The statement says: "If the coefficients are integers, then the roots must also be integers."
  4. To check this, we try an example: \(x^2 - 2 = 0\).
  5. Here, \(a = 1, b = 0, c = -2\). All are integers, so coefficients are integral.
  6. Now solve it: \(x^2 - 2 = 0 \implies x^2 = 2 \implies x = \pm \sqrt{2}\).
  7. But \(\sqrt{2}\) is not an integer (it is an irrational number).
  8. This shows that even if the coefficients are integers, the roots may not be integers.

Therefore, the statement is false.

NCERT Exemplar Solutions Class 10 – Mathematics – CHAPTER 4: Quadatric Equation – Exercise 4.2 | Detailed Answers