Q1 of 227 Page 82

Find the zeros of the following quadratic polynomials and verify the basic relationships between the zeros and the coefficients.

2x2 – 2√2 x + 1

Let f(x) = 2x2 – 2x + 1

To find out zeros of the given polynomial.


We put f(x) = 0


2x2 – 2x + 1 = 0


To find out roots of this polynomial we use splitting of middle term method.


According to this method we need to find two numbers whose sum is – 2 and product is 2.


2x2 – ()x + 1 = 0


2x2 x – x + 1 = 0


x(x – 1) – 1(x – 1) = 0


(x – 1)(x – 1) = 0


(x – 1)2 = 0


x = ,


Our zeros are α = and β = .


sum of zeros = α + β = +


sum of zeros = α + β =


Product of zeros = αβ = .


Now, Comparing f(x) = 2x2 – 2x + 1 with standard equation ax2 + bx + c.


We get, a = 2, b = – 2 and c = 1.


We can verify,


Sum of zeros =


i.e. α + β =


α + β =


Product of zeros =


αβ =


Hence, relationship between zeros and coefficient is verified.


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