Ask Dr. Math Domain and Range of a Function

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 Domain and Range of a Function, a selection of answers from the Dr. Math archives. Domain and Range Can you please explain about domain and range? Domain and Range of Functions I am learning in school about the domain and range of functions. Why are they called domain and range? And where did they come from? Finding the Domain of a Function How do you find the domain of this function: f(x) = (4+x)/(x^2-9)? Finding The Domain and Range of a Function How do I find the domain and range of a function? My problem is f(x) = x squared -2. How to Find the Range of a Function How do you find the range of a function like g(x) = (x+1)/(x^2-1)? Domain, Range, and Asymptote How do you find the domain, range, and asymptote of a function? Range If f(x) = x-3/x+3, I know the domain to be all Reals except for -3. The range, however, is all Reals except for 1. I don't know how they get the 1 algebraically. Range and Domain of a Graph Determine the domain and range of the graph of "f" that starts at (- 2,3), goes down to (0,0), and ends at (3,4). Range of a Function Describe the range of the function g(x) = e^(-2x). Natural Domain of a Function Some inputs don't make sense for some functions. Functions: Domain, Range, and Piecewise What are piecewise functions? What are open and closed points? How do you figure out the domain and range of a function without graphing it on a calculator? Domain and Range of x^x What is the domain and range of x^x? Domain and Range of an Inverse Function Why is the domain of a function equal to the range of the inverse function? Domain, Asymptotes, Intercepts of a Function What is the domain of this function? What asymptotes does it have? What are the x and y intercepts? Etc... Domain of a Composite Function I don't completely understand how to find the domain of a composite function. Could you please explain it?