-3/2√5, -½ find a quadratic polynomial whose sum and product respectively of the zeroes are as given. Also find the zeroes of these polynomials by factorisation
Solution:
Given, the sum of two zeros is -3/2√5.
Product of two zeros is -1/2.
We have to find the quadratic polynomial and its zeros.
A quadratic polynomial in terms of the zeroes (α,β) is given by
x2 - (sum of the zeroes) x + (product of the zeroes)
i.e, f(x) = x2 -(α +β) x +αβ
Here, sum of the roots, α +β = -3/2√5
Product of the roots, αβ = -1/2
So, the quadratic polynomial can be written as x² - (-3/2√5)x + (-1/2)
= x² + 3/2√5x - 1/2.
= 2√5x² + 3x - √5
Let 2√5x² + 3x - √5 = 0
On factoring the polynomial,
2√5x² - 2x + 5x - √5 = 0
2x(√5x - 1) + √5(√5x - 1) = 0
(2x + √5)(√5x - 1) = 0
Now, 2x + √5 = 0
2x = -√5
x = -√5/2
Also, √5x - 1 = 0
√5x = 1
x = 1/√5
Therefore, the zeros of the polynomial are 1/√5 and -√5/2
✦ Try This: Find a quadratic polynomial, the sum and product of whose zeroes are -√5 and 5√5, respectively. Also find its zeroes
☛ Also Check: NCERT Solutions for Class 10 Maths Chapter 2
NCERT Exemplar Class 10 Maths Exercise 2.4 Problem 1 (iv)
-3/2√5 and -½ find a quadratic polynomial whose sum and product respectively of the zeroes are as given. Also find the zeroes of these polynomials by factorisation
Summary:
A quadratic polynomial whose sum and product of zeroes are -3/2√5 and -1/2 is 2√5x² + 3x - √5. The zeros of the polynomial are 1/√5 and -√5/2
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