Recognizing a Function From a GraphDate: 09/03/2003 at 02:23:55 From: flora Subject: Explain how to tell if a graph represents a function I think I'm a bit confused about what a function is. How is it different from an equation? Date: 09/03/2003 at 06:13:13 From: Doctor Anthony Subject: Re: Explain how to tell if a graph represents a function A function requires that you get a single unique value of y for a given value of x. So if you draw a line, x=k (that is, a line parallel to the y axis), and it cuts the graph in one point only for all k, then you have a function. If the line cuts the graph in more than point for some values of k then we have a RELATION and not a function. Example of a function: y = 3x^2 + 2x - 1 Example of a relation: x^2 + y^2 = 4 - Doctor Anthony, The Math Forum http://mathforum.org/dr.math/ Date: 09/04/2003 at 00:54:54 From: flora Subject: Thank you Thanks! That was very clear! |
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