If one zero of the quadratic polynomial x² + 3x + k is 2, then the value of k is
a. 10
b. -10
c. 5
d. -5

Solution:

Given, the quadratic polynomial is x² + 3x + k.

One zero of the polynomial is 2.

We have to find the value of k.

Let f(x) = x² + 3x + k

f(2) = 0

Put x = 2 in the polynomial

(2)² + 3(2) + k = 0

4 + 6 + k = 0

10 + k = 0

k = -10

Therefore, the value of k is -10

✦ Try This: If one zero of the quadratic polynomial x² + 3x + k is 3, then the value of k is

Given, the quadratic polynomial is x² + 3x + k

One zero of the polynomial is 3

We have to find the value of k

Let f(x) = x² + 3x + k

f(3) = 0

Put x = 3 in the polynomial

(3)² + 3(3) + k = 0

9 + 9 + k = 0

18 + k = 0

k = -18

Therefore, the value of k is -18

☛ Also Check: NCERT Solutions for Class 10 Maths Chapter 2

NCERT Exemplar Class 10 Maths Exercise 2.1 Solved Problem 1

If one zero of the quadratic polynomial x² + 3x + k is 2, then the value of k is a. 10 b. -10 c. 5 d. -5

Summary:

If one zero of the quadratic polynomial x² + 3x + k is 2, then the value of k is -10

☛ Related Questions:

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