Subscribe to our Youtube Channel - https://you.tube/teachoo
Ex 9.3, 6 - Chapter 9 Class 11 Sequences and Series
Last updated at May 29, 2018 by Teachoo
Transcript
Ex 9.3,6 For what values of x, the numbers (โ2)/7, x, (โ7)/2 are in G.P? Since (โ2)/7, x, (โ7)/2 are in GP So common ratio will be same Common ratio (r) = (๐๐๐๐๐๐ ๐ก๐๐๐ )/(๐น๐๐๐ ๐ก ๐ก๐๐๐) = ๐ฅ/((โ2)/7) = 7๐ฅ/(โ2) Also, Common ratio (r) = (๐โ๐๐๐ ๐ก๐๐๐ )/(๐๐๐๐๐๐ ๐ก๐๐๐) = ((โ7)/2)/๐ฅ = (โ7)/2๐ฅ From (1) & (2) 7๐ฅ/(โ2) = (โ7)/2๐ฅ 7x ร 2x = (-7) ร (-2) 14x2 = 14 x2 = 14/14 x2 = 1 x = ยฑ โ1 x = ยฑ1 So, x = 1 or x = -1 GP is (โ2)/7, x, (โ7)/2 For x = 1, GP is (โ2)/7, 1, (โ7)/2 For x = โ1, GP is (โ2)/7, โ1, (โ7)/2 Hence possible numbers in GP are (โ2)/7, 1, (โ7)/2 or (โ2)/7, โ1, (โ7)/2
Geometric Progression(GP): Formulae based
Ex 9.3, 6
You are here
Example 9
Ex 9.3, 1
Example 10
Ex 9.3, 5
Ex 9.3, 2
Example 11
Ex 9.3, 4
Ex 9.3, 3 Important
Ex 9.3, 17 Important
Example 12
Ex 9.3, 7
Ex 9.3, 10
Ex 9.3, 9
Ex 9.3, 11 Important
Ex 9.3, 8
Ex 9.3, 19
Ex 9.3, 20
Example 13
Ex 9.3, 13
Ex 9.3, 15
Ex 9.3, 16
Ex 9.3, 21
Ex 9.3, 14
Misc 9
Misc 8
Example 14 Important
Ex 9.3, 12
Example 15 Important
Ex 9.3, 18 Important
Misc 21 Not in Syllabus - CBSE Exams 2021
Misc 11
Misc 7 Important
Chapter 9 Class 11 Sequences and Series
Concept wise
- Finding Sequences
- Arithmetic Progression (AP): Formulae based
- Arithmetic Progression (AP): Statement
- Arithmetic Progression (AP): Calculation based/Proofs
- Inserting AP between two numbers
- Arithmetic Mean (AM)
- Geometric Progression(GP): Formulae based
- Geometric Progression(GP): Statement
- Geometric Progression(GP): Calculation based/Proofs
- Inserting GP between two numbers
- Geometric Mean (GM)
- AM and GM (Arithmetic Mean And Geometric mean)
- AP and GP mix questions
- Finding sum from series
- Finding sum from nth number
About the Author
Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.