NCERT Solutions
Class 9 - Mathematics - Chapter 2: POLYNOMIALS
EXERCISE 2.2

Question. 1

Find the value of the polynomial \(5x - 4x^2 + 3\) at:

(i) \(x = 0\)
(ii) \(x = -1\)
(iii) \(x = 2\)

Answer:

(i) 3

(ii) -6

(iii) -3

Question. 2

Find \(p(0)\), \(p(1)\), and \(p(2)\) for each of the following polynomials:

(i) \(p(y) = y^2 - y + 1\)
(ii) \(p(t) = 2 + t + 2t^2 - t^3\)
(iii) \(p(x) = x^3\)
(iv) \(p(x) = (x - 1)(x + 1)\)

Answer:

(i) 1, 1, 3

(ii) 2, 4, 4

(iii) 0, 1, 8

(iv) -1, 0, 3

Question. 3

Verify whether the following are zeroes of the polynomial, as indicated:

(i) \(p(x) = 3x + 1\), \(x = -\dfrac{1}{3}\)
(ii) \(p(x) = 5x - \pi\), \(x = \dfrac{4}{5}\)
(iii) \(p(x) = x^2 - 1\), \(x = 1, -1\)
(iv) \(p(x) = (x + 1)(x - 2)\), \(x = -1, 2\)
(v) \(p(x) = x^2\), \(x = 0\)
(vi) \(p(x) = lx + m\), \(x = -\dfrac{m}{l}\)
(vii) \(p(x) = 3x^2 - 1\), \(x = -\dfrac{1}{\sqrt{3}}, \dfrac{2}{\sqrt{3}}\)
(viii) \(p(x) = 2x + 1\), \(x = \dfrac{1}{2}\)

Answer:

(i) Yes

(ii) No

(iii) Yes

(iv) Yes

(v) Yes

(vi) Yes

(vii) \(-\dfrac{1}{\sqrt{3}}\) is a zero, but \(\dfrac{2}{\sqrt{3}}\) is not a zero

(viii) No

Question. 4

Find the zero of the polynomial in each of the following cases:

(i) \(p(x) = x + 5\)
(ii) \(p(x) = x - 5\)
(iii) \(p(x) = 2x + 5\)
(iv) \(p(x) = 3x - 2\)
(v) \(p(x) = 3x\)
(vi) \(p(x) = ax\), \(a \neq 0\)
(vii) \(p(x) = cx + d\), where \(c, d\) are real numbers

Answer:

(i) -5

(ii) 5

(iii) -\dfrac{5}{2}

(iv) \dfrac{2}{3}

(v) 0

(vi) 0

(vii) -\dfrac{d}{c}

NCERT Solutions Class 9 – Mathematics – Chapter 2: POLYNOMIALS – EXERCISE 2.2 | Detailed Answers