Question 2 (OR 2 nd question)

Find the value(s) of k for which the equation x 2 + 5kx + 16 = 0 has real and equal roots

Find value of k for which equation x^2 + 5kx + 16 = 0 has real and

Question 2 (Or 2nd) - CBSE Class 10 Sample Paper for 2019 Boards - Part 2

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Question 2 (OR 2nd question) Find the value(s) of k for which the equation x2 + 5kx + 16 = 0 has real and equal roots x2 + 5kx + 16 = 0 Comparing equation with ax2 + bx + c = 0 a = 1, b = 5k , c = 16 Since the equation has 2 equal roots, D = 0 b2 – 4ac = 0 Putting values (5k)2 – 4 × 1 × 16 = 0 25k2 – 64 = 0 25k2 = 64 k2 = 64/25 k2 = 8^2/5^2 k2 = (8/5)^2 k = ± √((8/5)^2 ) k = ± 8/5 ∴ k = ± 8/5

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Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science and Computer Science at Teachoo