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Find a quadratic polynomial each with the given numbers as the sum and product of its zeroes respectively. 14,-1 - Mathematics

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Question

Find a quadratic polynomial each with the given numbers as the sum and product of its zeroes respectively. 

`1/4 , -1`

Sum

Solution

Given: α + β = `1/4`, αβ = -1

Since ax2 + bx + c = kx2 - k(α + β)x + kαβ

In comparison,

a = k, b = -k(α + β) and c = kαβ

α + β = `(-b)/a = 1/4` and αβ = `c/a = -1`

⇒ a = 4

⇒ b = -4(α + β) 

⇒ c = kαβ = 4(-1)

Hence, on writing as ax2 + bx + c

⇒ 4x2 - 4(α + β)x + 4(αβ)

⇒ `4x^2 - 4(1/4)x + 4(-1)`

⇒ 4x2 - x - 4

The quadratic polynomial is 4x2 - x - 4.

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Chapter 2: Polynomials - Exercise 2.2 [Page 33]

APPEARS IN

NCERT Mathematics [English] Class 10
Chapter 2 Polynomials
Exercise 2.2 | Q 2.1 | Page 33

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