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MHT CET202014 Oct 2020Morning ShiftMathematicsSequences and SeriesActual

For a sequence (t_ n ) if s_ n =7 (3^ n -1 ) , then t_ n =

Options

  1. A(7) 3^ n-1
  2. B(14) 3^ n+1
  3. C(14) 3^ n-1
  4. D(7) 3^ n+1

Correct answer

C. (14) 3^ n-1

Step-by-step solution

A sequence; t_ n ; aligned s_ n &=7 (3^ n-1 ) s_ n-1 &=7 (3^ n-1 -1 ) & aligned aligned t_ n &=s_ n -s_ n-1 t_ n &=7 (3^ n -3^ n-1 ) &=7 3^ n-1 2 &=14 3^ n-1 aligned

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