1. Chapter 8 Class 11 Sequences and Series
  2. Serial order wise
  3. Ex 8.2
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Ex 8.2, 6 - Chapter 8 Class 11 Sequences and Series

Last updated at Dec. 16, 2024 by Teachoo

Transcript

Ex 8.2,6 For what values of x, the numbers (−2)/7, x, (−7)/2 are in G.P? Since (−2)/7, x, (−7)/2 are in GP So common ratio will be same Common ratio (r) = (𝑆𝑒𝑐𝑜𝑛𝑑 𝑡𝑒𝑟𝑚 )/(𝐹𝑖𝑟𝑠𝑡 𝑡𝑒𝑟𝑚) = 𝑥/((−2)/7) = 7𝑥/(−2) Also, Common ratio (r) = (𝑇ℎ𝑖𝑟𝑑 𝑡𝑒𝑟𝑚 )/(𝑆𝑒𝑐𝑜𝑛𝑑 𝑡𝑒𝑟𝑚) = ((−7)/2)/𝑥 = (−7)/2𝑥 From (1) & (2) 7𝑥/(−2) = (−7)/2𝑥 7x × 2x = (-7) × (-2) 14x2 = 14 x2 = 14/14 x2 = 1 x = ± √1 x = ±1 So, x = 1 or x = -1 GP is (−2)/7, x, (−7)/2 For x = 1, GP is (−2)/7, 1, (−7)/2 For x = –1, GP is (−2)/7, –1, (−7)/2 Hence possible numbers in GP are (−2)/7, 1, (−7)/2 or (−2)/7, –1, (−7)/2
  1. Chapter 8 Class 11 Sequences and Series
  2. Serial order wise

    3. Ex 8.2

    Examples →
Examples →
Chapter 8 Class 11 Sequences and Series
Serial order wise

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Davneet Singh

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