When the polynomial 1-2x+3x^2-4x^3+..... -78x^78+79x^79 is divided by x-1, the remainder is
option
a) 39
b) -39
c) x+1
d) 41
e) 40

• the series is wrong....look the series again ....look at position of 78x^78+79x^79...and 3x^2-4x^3..
• 10 years agoHelpfull: Yes(26) No(2)
• answer is c(x+1)
  if we put x=-1, then series will be (1+2+....+79)/-2 that leaves remainder 0 and (x+1)=0
• 10 years agoHelpfull: Yes(22) No(2)
• answer is 40
  
  for the remainder put x=1 in the polynomial and whatever the answer comes is the remainder
  by putting 1 we get
  1-2+3-4+5.....-78+79
  here we have can arrange the series as
  (1+3+5+....+79)-(2+4+6+...78)
  both are in arithmetic progression with both having common difference as 2
  solving we get answer as 40
  
• 10 years agoHelpfull: Yes(19) No(21)
• when we take x=1....wont it be smthng divided by 0..dat is indifinite???
• 10 years agoHelpfull: Yes(6) No(3)
• Ans= -39
  putting x=1 in above polynomial
  
  -1+2(1)+[3(1)^2]-[4(1)^3].... [79(1)^79]
  now when we take 2 terms at a time.. it will give -1 each.. ex. -1+2(1)=1 ; [3(1)^2]-[4(1)^3]= -1
  so when we add all.. it will give -39
• 10 years agoHelpfull: Yes(3) No(8)
• which is the corect ans... and how is it comming?? plz help
• 10 years agoHelpfull: Yes(2) No(0)
• 41
  substitute x=1 in d given equation we get
  remainder as 41
  
• 10 years agoHelpfull: Yes(0) No(9)