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Most Important Selected Qs for JEE AdvancedMathematicsSequences and Series

Let a, b, c (in order) be the first three terms of a sequence and satisfying ( 8 b^3-a^3-c^3 6 a b c )=0 and b= (a^2-4 )= (c-2) . If T_n and S_n denote n^ th term and sum of first n terms of the sequence, then:

Options

  1. AT₁₀=31
  2. BS₁₀=120
  3. CT₂₁^2-2 T₂₁ T₁+2 T₁^2=1609
  4. DS₁₁-S₁₀=23

Correct answer

D. S₁₁-S₁₀=23

Step-by-step solution

aligned & 8 b^3-a^3-c^3=6 a b c & a^3+(-2 b)^3+c^3=3 a(-2 b) c aligned a-2 b+c=0 a, b, c are in A.P. a=3, b=5, c=7 Now, verify the options.

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