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

(i) 1/4, -1  (ii) √2, 1/3  (ii) 0, √5  (iv) 1, 1  (v) -1/4, 1/4   (vi) 4, 1

Solution:

(i) 1/4, -1 

From the formulas of sum and product of zeroes, we know,

Sum of zeroes = α + β

Product of zeroes = α β

Sum of zeroes = α + β = 1/4

Product of zeroes = α β = -1

∴ If α and β are zeroes of any quadratic polynomial, then the quadratic polynomial equation can be written directly as:-

x2 – (α + β)x + αβ = 0

x2 – (1/4)x + (-1) = 0

4x2 – x – 4 = 0

Thus, 4x2 – x – 4 is the quadratic polynomial.

(ii) √2, 1/3

Sum of zeroes = α + β =√2

Product of zeroes = α β = 1/3

∴ If α and β are zeroes of any quadratic polynomial, then the quadratic polynomial equation can be written directly as:-

x2 – (α + β)x + αβ = 0

x2 –(√2)x + (1/3) = 0

3x2 – 3√2x + 1 = 0

Thus, 3x2 – 3√2x + 1 is the quadratic polynomial.

(iii) 0, √5

Given,

Sum of zeroes = α + β = 0

Product of zeroes = α β = √5

∴ If α and β are zeroes of any quadratic polynomial, then the quadratic polynomial equation can be written directly as:-

x2 – (α + β)x + αβ = 0

x2 – (0)x + √5 = 0

Thus, x2 + √5 is the quadratic polynomial.

(iv) 1, 1

Given,

Sum of zeroes = α + β = 1

Product of zeroes = α β = 1

∴ If α and β are zeroes of any quadratic polynomial, then the quadratic polynomial equation can be written directly as:-

x2 – (α + β)x + αβ = 0

x2 – x + 1 = 0

Thus, x2 – x + 1 is the quadratic polynomial.

(v) -1/4, 1/4

Given,

Sum of zeroes = α+β = -1/4

Product of zeroes = α β = 1/4

∴ If α and β are zeroes of any quadratic polynomial, then the quadratic polynomial equation can be written directly as:-

x2–(α+β)x +αβ = 0

x2–(-1/4)x +(1/4) = 0

4x2+x+1 = 0

Thus, 4x2+x+1 is the quadratic polynomial.

(vi) 4, 1

Given,

Sum of zeroes = α + β = 4

Product of zeroes = αβ = 1

∴ If α and β are zeroes of any quadratic polynomial, then the quadratic polynomial equation can be written directly as:-

x2 – (α + β)x + αβ = 0

x2 – 4x + 1 = 0

Thus, x2 – 4x + 1 is the quadratic polynomial.