The sum of the series 1 + 1(1+1/n) + 3(1+1/n)2 + ..... is equal to?

• answer please
  
  
• 12 years agoHelpfull: Yes(1) No(3)
• 1+1,3,5,7___(1+1/n)1,2,3,4,5___
  
  1+(1+(n-1)2)(1+1/n)n
  
  1+(2n-1)(n+1/n)(n)
  
  1+(2n-1)(n+1)
  
  1+2n*n+n-1
  
  2n*n+n ANS
• 12 years agoHelpfull: Yes(1) No(7)
• let 1+1/n be p
  so this becomes 1+p+3p^2+.....
  now 1+p(1+3p+.....)=1+p(1-p)^-3
  =1+((n+1)/n)(1-1-1/n)^-3
  =1+((n+1)/n)(-1/n)^-3
  =1-n^3-n^2
• 12 years agoHelpfull: Yes(1) No(7)