Functions and Function Tables
Date: 05/11/99 at 17:14:53 From: chris Subject: I don't understand functions and function tables I asked my parents and various other people about functions but they know absolutely nothing! I do not understand functions and function tables. Can you help me?
Date: 05/20/99 at 13:48:47 From: Doctor Schwa Subject: Re: I don't understand functions and function tables One way to think of a function is as a rule. You give it some object, and it replies with some other object. For example, a catalog for a shirt company might have a function called price, and price of green shirt = $8 could be written as price(green shirt) = 8 and we might also have price(white shirt) = 6 and price(yellow shirt) = 8 and price(tie-dye shirt) = 12 and so on. In math, functions are usually rules that work with numbers. The object you give is a number, and the reply is another number. For instance, the function rule might be "add two," and if we name that function f, f(4) = 6 f(5) = 7 and so on. In general we could write f(x) = x+2. Now, if you want to make a function table, you take a rule, say g(x) = x^2, and make a table like this: x | g(x) ---+----- -2 | 4 -1 | 1 0 | 0 1 | 1 2 | 4 and so on. You could continue the table as long as you want to. I hope this helps clear things up for you! If you have more questions about functions, please do write back. - Doctor Schwa, The Math Forum http://mathforum.org/dr.math/
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