Polynomials

Exercise 2.2 Part 4

Question: 4 – Find the zero of the polynomial in each of the following cases:

(i) p(x) = x + 5

Answer:To find the zero of the polynomial, we equate the given polynomial with zero.

Let, x + 5 = 0
Then, x = - 5

Thus, - 5 is the zero of the polynomial.

(ii) p(x) = x – 5

Answer: Given, p(x) = x – 5
Let, x – 5 = 0
Then, x = 5

Thus, 5 is the zero of the polynomial.

(iii) p(x) = 2x + 5

Answer: Given, p(x) = 2x + 5
Let, 2x + 5 = 0
Or, 2x = - 5
Or, x = - 5/2

Thus, - 5/2 is the zero of the polynomial

(iv) p(x) = 3x – 2

Answer: Given, p(x) = 3x – 2
Let, 3x – 2 = 0
Or, 3x = 2
Or, x = 2/3

Thus, 2/3 is the zero of the polynomial.

(v) p(x) = ax, a ≠ 0

Answer: Given, p(x) = ax, a≠ 0
Let, p(x) = 0
Or, ax = 0
Or, x = 0/a
Or, x = 0
Therefore, 0 is the zero of the given polynomial.

(vi) p(x) = cx + d, c≠ and c , d are real numbers

Answer: Given, p(x) = cx + d, c ≠ 0
Let, p(x) = 0
Or, cx + d = 0
Or, cx = - d
Or, x = - d/c
Here, - d/c is zero of the given polynomial.