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| Question 1160164:  If f(x+y)=f(x)+f(y) and f(1)=17, find f(2), f(3), and f(4). Is f(x+y)=f(x)+f(y) for all functions?
 f(2)=
 f(3)=
 f(4)=
 Answer by ikleyn(52879)
      (Show Source): 
You can put this solution on YOUR website! . 
 
then  f(2) = f(1 + 1) = f(1) + f(1) = 17 + 17 = 34.     ANSWER
      f(3) = f(1 + 2) = f(1) + f(2) = 17 + 34 = 51.     ANSWER
      f(4) = f(2 + 2) = f(2) + f(2) = and you continue from this point.
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 For the last question, the answer is  "NO".
 
 As an counterexample, consider f(x) = x^2.
 
 
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