If A1=2 and An+1=An +2n then find A100....(the n values are in subscript with A)

• answer is 9902
  A100= 2 + 1*2 + 2*2 + 3*2 + ....... 99*2
  A100 = 2 + 2(1+2+3+.....+99)
  A100 = 2 + 9900
  A100 = 9902
• 12 years agoHelpfull: Yes(38) No(5)
• ans is 19802
  common diff=2n
  so Tn=a+(n-1)d
  or Tn=2+2n^2-2n
  put n=100
  we get 19802
• 12 years agoHelpfull: Yes(7) No(17)
• ans 9902 is correct
  A100= 2 + 1*2 + 2*2 + 3*2 + ....... 99*2
  A100 = 2 + 2(1+2+3+.....+99)
  A100 = 2 + 9900
  A100 = 9902
• 12 years agoHelpfull: Yes(5) No(0)
• ans 9902 is true
• 12 years agoHelpfull: Yes(3) No(0)
• use n^2-n+2 by carefully observing the iteration &ans is 9902 by putting n=100
• 12 years agoHelpfull: Yes(2) No(1)
• Ans:-19802
  common diff=(An+1-An)=2n.
  so; Tn=a+(n-1)d
  or Tn=2+2n^2-2n
  put n=100
  we get 19802
• 12 years agoHelpfull: Yes(2) No(4)
• ans is 2
  because we know only the value of a1 so we substitute a100 as A99+2*99 and ,a99 as A98+2*98,......... in this way we write A1 as A0+1=A1+0*2
  
  so we get ans as 2 only
  
• 12 years agoHelpfull: Yes(1) No(5)
• AMIT GAUTAM IS CORRECT ANS IS 19802
• 12 years agoHelpfull: Yes(0) No(14)
• for solving such series
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• AMIT GAUTAM can u tell me how u get common diff =2n plz any budy tell me
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