Misc 6 - Solve 3x2 - 4x + 20/3 = 0 - Chapter 5 NCERT - Quadaratic equation

Misc 6 - Chapter 5 Class 11 Complex Numbers - Part 2

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Question 2 Solve the equation 3𝑥2 – 4𝑥 + 20/3 = 0 3𝑥2 – 4𝑥 + 20/3 = 0 Multiplying both sides by 3 3 × (3𝑥2 – 4𝑥 "+ " 20/3) = 3 × 0 3 × 3x2 – 3 × 4x + 3 × 20/3 = 0 9𝑥2 – 12𝑥 + 20 = 0 The above equation is of the form 𝑎𝑥2 + 𝑏𝑥 + 𝑐 = 0 Where a = 9, b = –12, and c = 20 x = (−𝑏±√( 𝑏^2 −4𝑎𝑐 ))/2𝑎 = (−(−12) ± √((−12)^2 − 4 × 9 × 20))/(2 × 9) = (12 ± √(144 −720))/18 = (12 ± √(−576))/18 = (12 ± √(−1 × 576))/18 = (12 ± √(−1 ) × √( 576))/18 = (12 ± 𝑖 × √( 576))/18 = (12 ± 𝑖 × √( 242))/18 = (12 ± 𝑖 × 24)/18 = (6(2 ± 𝑖 × 4))/18 = ((2 ± 𝑖 × 4))/3 = ((2 ± 𝑖4))/3 Thus, 𝑥 = ((2 ± 𝑖4))/3

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Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 13 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.