# SOLUTION: 1)The first two terms of a geometric sequence are a1=1/3 and a2=1/6. what is a8 the 8th term? 2)If x is inversely proportional to y and x =60 when y =0.5 find x when x=12 3)

Algebra ->  Algebra  -> Sequences-and-series -> SOLUTION: 1)The first two terms of a geometric sequence are a1=1/3 and a2=1/6. what is a8 the 8th term? 2)If x is inversely proportional to y and x =60 when y =0.5 find x when x=12 3)      Log On

 Ad: Algebra Solved!™: algebra software solves algebra homework problems with step-by-step help! Ad: Algebrator™ solves your algebra problems and provides step-by-step explanations!

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

 Question 55486: 1)The first two terms of a geometric sequence are a1=1/3 and a2=1/6. what is a8 the 8th term? 2)If x is inversely proportional to y and x =60 when y =0.5 find x when x=12 3)An infinite geometric series has 1 ad 1/5 as its first 2 terms: 1, 1/5, 1/25, 1/125,... what is the sum, S, of the infinite series? 4) if y=7.2 when x=10 what is the value of x when y =20? (y varies inversely as the square of x)Answer by stanbon(57307)   (Show Source): You can put this solution on YOUR website!1)The first two terms of a geometric sequence are a1=1/3 and a2=1/6. what is a8 the 8th term? r=(1/6)/(1/3) = 1/2 a(8)= ar^7 = (1/3)(1/2)^7 = 1/3*1/128= 1/384 ---------------- 2)If x is inversely proportional to y and x =60 when y =0.5 find x when x=12 y=k/x 0.5=k/60 k=30 So y=30/x I assume you meant to say "find y when x=12". If so, y=30/12 = 5/2 ---------------- 3)An infinite geometric series has 1 ad 1/5 as its first 2 terms: 1, 1/5, 1/25, 1/125,... what is the sum, S, of the infinite series? What methods are you using to find the sum of an infinite series? --------------- 4) if y=7.2 when x=10 what is the value of x when y =20? (y varies inversely as the square of x) y=k/x^2 7.2=k/(100) k=720 So, y = 720/x^2 20=720/x^2 x^2=720/20 x^2=36 x=6 or x=-6 Cheers Stan H.