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CBSE - Mathematics - Polynomials

Polynomials

NCERT Exercise Exercise 2.2

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

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) = axa ≠ 0
(vii) p(x) = cx + d, c ≠ 0, c, are real numbers.

 

Answer

 

(i) p(x) = x + 5 

p(x) = 0

x + 5 = 0

x = -5

Therefore, x = -5 is a zero of polynomial p(x) = x + 5 .

 

(ii) p(x) = x - 5

p(x) = 0

x - 5 = 0

x = 5

Therefore, x = 5 is a zero of polynomial p(x) = x - 5.

 

(iii) p(x) = 2x + 5

p(x) = 0

2x + 5 = 0
2x = -5
x = -5/2
Therefore, x = -5/2 is a zero of polynomial p(x) = 2x + 5.

(iv) p(x) = 3x - 2
p(x) = 0
3x - 2 = 0
x = 2/3
Therefore, x = 2/3 is a zero of polynomial p(x) = 3x - 2.

(v) p(x) = 3x
p(x) = 0
3x = 0
x = 0
Therefore, x = 0 is a zero of polynomial p(x) = 3x.

(vi) p(x) = ax
p(x) = 0
ax = 0
= 0
Therefore, x = 0 is a zero of polynomial p(x) = ax.

(vii) p(x) = cx + d
p(x) = 0
cx + d = 0
x = -d/c
Therefore, x = -d/c is a zero of polynomial p(x) = cx + d.

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