# SOLUTION: URGENT QUESTION... the question is- if a sequence follows the same pattern as a, ar, ar^2... and t4=8 and t7=1 find a, r, and t10 thanks

Algebra ->  Algebra  -> Sequences-and-series -> SOLUTION: URGENT QUESTION... the question is- if a sequence follows the same pattern as a, ar, ar^2... and t4=8 and t7=1 find a, r, and t10 thanks      Log On

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 Algebra: Sequences of numbers, series and how to sum them Solvers Lessons Answers archive Quiz In Depth

 Question 207864: URGENT QUESTION... the question is- if a sequence follows the same pattern as a, ar, ar^2... and t4=8 and t7=1 find a, r, and t10 thanksAnswer by RAY100(1637)   (Show Source): You can put this solution on YOUR website!geometric sequence ,,,t(n) = a(1) r^(n-1) . given,,,t(4) =a r^(4-1) =ar^3 =8 . given,,,t(7) =ar^(7-1) = ar^6 =1 . (ar^6 =1)/(ar^3 = 8) . r^(6-3) =1/8 . r^3 = 1/8,,,,take cube root . r= .5 ,,,,,answer . subst,,,,ar^3=8,,,,a*(.5)^3 =8,,,,,a=64,,,,answer . check,,,,ar^3=8,,,,,(64)* .5^3 = 8,,,,,,ok . ar^6=1,,,,,,(64)*.5^6 =1,,,,,ok . to find t(10) =ar^(10-1) =ar^9 =(64)*.5^9 = .125 = 1/8,,,answer