Question

If one zero of quadratic polynomial (kx2+3x+k) is 2, then the value of k is​

Answer 1

$\underline{\underline{\blue{\textbf{Step - By - Step - Explanation : -}}}}$

To Find :

• value of k

Solution :

• one zero of Given polynomialis 2.
• x = 2

• Substituting value of x in given Polynomial

p(x) = kx² + 3x + k

›› k × (2)² + 3 × 2 + k

›› k × 4 + 6 + k

›› 4k + k + 6

›› 5k + 6

›› 5k = -6

›› k = -6/5

Hence

• value of k is -6/5

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Answer 2

Answer:

-6/5 [or -1.2]

Step-by-step explanation:

The zero of the polynomial is defined as any real value of x, for which the value of the polynomial becomes zero.

Given, P(x) = kx²+3x+k

Since 2 is the zero of the polynomial, P(2) = 0

So,

P(2) = k×(2)² + 3×2+ k

P(2) = 4k + 6 + k

P(2) = 5k + 6

Therefore,

5k + 6 = 0

=> 5k = -6

=> k = -6/5 = -1.2