The sequence{An} is defined by A1 = 2 and An+1=An+2n what is the value of A100?

• An=2+n*(n-1)
  A100=9902
• 11 years agoHelpfull: Yes(17) No(1)
• a1=2
  a2=4
  a3=8
  a4=14.............so on
  2,4,8,14 the diff is 2 then an=an2+bn+c
  a1=a+b+c=2
  a2=4a+2b+c=4
  a3=9a+3B+c=8
  find the values of a,b,c
  a=1,b=-1,c=2
  An=n2-b+c
  put n=100
  (100)2-100+2=9902 is the ans..
• 11 years agoHelpfull: Yes(13) No(2)
• A100 will be 9902 !
• 11 years agoHelpfull: Yes(5) No(3)
• A1=1
  A2=5
  A3=11
  A4=19
  A5=29
  ...
  ...
  ...
  A100=397
• 11 years agoHelpfull: Yes(0) No(13)
• ans will be 9900
• 11 years agoHelpfull: Yes(0) No(6)
• ans:- 200 is it corrrect.
  if a(1)=2
  so a(100)=200
• 11 years agoHelpfull: Yes(0) No(10)
• a1=2
  a2=a1+2*2=2+4=6
  a3=a2+2*3=6+6=12
  this follow a pattern
  a1=1*1+1=2
  a2=2*2+2=6
  a3=3*3+3=12
  a4=4*4+4=20
  an=n*n+n
  so a100=100*100+100=10100 ans
  
• 9 years agoHelpfull: Yes(0) No(1)