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27. if a and B are the zeros of the quadratic polynomial f(x) = 6x2 + x - 2, find the value of α/β+β/α |
Answer» Answer:-Given Polynomial: 6x² + x - 2 Let a = 6 ; b = 1 ; c = - 2 We know that, Sum of the zeroes = - b/a → α + β = - 1/6 -- equation (1)Product of the zeroes = c/a → αβ = - 2/6 → αβ = - 1/3 -- equation (2)We have to find: α/β+β/α = ? Taking LCM we get, → ( α² + β² ) / αβ We know that, (a + b)² = a² + b² + 2ab → (a + b)² - 2ab = a² + b² → (α + β)² - 2αβ = α² + β² Hence, → [ (α + β)² - 2αβ ] / αβ Putting the VALUES from equation (1) and (2) we get, → [ ( - 1/6)² - 2( - 1/3) ] / (- 1/3) → [ 1/36 + 2/3 ] / ( - 1/3) → [ (1 + 24) / 36 ] * ( - 3) → 25 / 36 * ( - 3) → - 25 / 12Hence, the value of α/β + β/α is - 25/12. |
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