Ex 8.2, 10 - Chapter 8 Class 11 Sequences and Series
Last updated at Dec. 16, 2024 by Teachoo
Geometric Progression(GP): Formulae based
Ex 8.2, 6
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Chapter 8 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)
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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
Transcript
Ex 8.2, 10 Find the sum to n terms in the geometric progression x3, x5, x7….. (if x ≠ ± 1) x3, x5, x7….. We know that Sn = (a(1 − 𝑟^𝑛))/(1 − r) where Sn = sum of n terms of GP n is the number of terms a is the first term r is the common ratio Here, First term a = x3 Common ratio r = 𝑥5/𝑥3 = x2 Now, ∴ Sum of n terms = (a[1 − 𝑟^𝑛])/(1 − r) Putting values a = x3 & r = x2 Sn = (x3[1 − (x2)n])/(1 − x2) = (x3(1 − x2n))/(1 − x2) Hence sum of n terms is (𝑥3 [ 1 − 𝑥2𝑛])/(1 −𝑥2)
