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| Question 198061:  Which of the following are functions?  The last two problems, i.e., b & c, are multi part relations consider all parts when determining whether or not these relations are functions.  Explain your reasoning for a, b, and c.
 a. f(x) = x + 5
 b. f(x) = 3 if x>2 otherwise f(x) = -2
 c. f(x) = 7 if x>0  or  f(x) = -7 if x<0  or  f(x) = 7 or -7 if x = 0
 Answer by solver91311(24713)
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You can put this solution on YOUR website! 
 The mathematical concept of a function expresses dependence between two quantities, one of which is known and the other which is produced. A function associates a single output to each input element drawn from a fixed set, such as the real numbers (
  ), although different inputs may have the same output. 
 a.  Function.  No value of x will result in more than one value for f(x)
 
 b.  Function.  Same reason.
 
 c.  Not a function.  If x = 0, then f(x) is 7 or -7, violating the restriction of a single output for each input element.
 
 
 John
 
  
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