Ex 2.2, 1 - Find zeroes of following quadratic polynomials - Ex 2.2

Ex 2.2, 1 - Chapter 2 Class 10 Polynomials - Part 2

  1. Chapter 2 Class 10 Polynomials (Term 1)
  2. Serial order wise

Transcript

Ex 2.2, 1(i) Find the zeroes of the following quadratic polynomials and verify the relationship between the zeroes and the coefficients. x2 – 2x – 8 Let p(x) = x2 – 2x – 8 Zero of the polynomial is the value of x where p(x) = 0 Putting p(x) = 0 x2 – 2x – 8 = 0 We find roots using splitting the middle term method x2 – 4x + 2x – 8 = 0 x(x – 4) + 2(x – 4) = 0 (x + 2)(x − 4) = 0 So x = −2, 4 Therefore, α = – 2 & β = 4 are the zeroes of the polynomial p(x) = x2 – 2x – 8 = 1x2 – 2x – 8 Comparing with ax2 + bx + c So a = 1 , We verify Sum of zeroes = − (𝐶𝑜𝑒𝑓𝑓𝑖𝑐𝑖𝑒𝑛𝑡 𝑜𝑓 𝑥)/(𝐶𝑜𝑒𝑓𝑓𝑖𝑐𝑖𝑒𝑛𝑡 𝑜𝑓 𝑥2) i.e. α + β = - 𝑏/𝑎 Since, L.H.S = R.H.S Hence relationship between zeroes & coefficient is verified

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Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 10 years. He provides courses for Maths and Science at Teachoo.