1203 What's a Geometric Sequence?

3003 days ago by MATH4R2012

#1) {2,6,18,54,...} r=3 ([2*3^n for n in range(10)]) show(sum([2*3^n for n in range(10)])) 
       
#2) {1,1/2,1/4,1/8,...} r=1/2 show([(1*(1/2)^n).n() for n in range(15)]) show(sum([1*(1/2)^n for n in range(15)]).n()) 
       

#3) 0.99999... = .9 + .09 + .009 + ... .9/(1-.1) 
       
#4) 0.33333... a/(1-r) (3/10)/(1-(1/10)) 
       
#p838(72) {1000,900,810,...} a/(1-r) 1000/(1-(9/10)) 
       
#p838(72) {1000,900,810,...} a(1-r^(n+1))/(1-r) 1000*(1-.9^50)/(1-.9) 
       
sum([1000*.9^n for n in range(50)])