The zeroes of the polynomial r(t) = −12t 2 + (k − 3)t + 48 are negative of each other. Then k is

(a) 3   (b) 0   (c) −1.5   (d) −3

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  1. Class 10
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Question 45 The zeroes of the polynomial r(t) = −12t2 + (k − 3)t + 48 are negative of each other. Then k is (a) 3 (b) 0 (c) −1.5 (d) −3 Given r(t) = −12t2 + (k − 3)t + 48 Since zeros are negative of each other Let zeroes of r(t) be 𝛼 and −𝛼 Now, Sum of Zeroes = (−𝑏)/𝑎 0 = (−(𝒌 − 𝟑))/(−𝟏𝟐) 0 = ((𝑘 − 3))/12 0 = k − 3 3 = k k = 3 So, the correct answer is (a)

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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.