One-to-one functions and inverse functions.

In summary, a one-to-one function is a type of mathematical function where each input has exactly one corresponding output. To determine if a function is one-to-one, you can use the horizontal line test. An inverse function is a function that "undoes" the original function, and it can be found by switching the positions of the input and output variables. A function can only have one inverse, as it must "undo" the original function and multiple inverse functions would create ambiguity.
  • #1
SherlockOhms
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I was just wondering if inverse functions only apply to one-to-one functions?(Or a function who's domain has been restricted to act as a one-to-one function). Thanks.
 
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  • #2
Yes, the function has to be one-to-one in order to have an inverse. For example, f(x) = x2 is not one-to-one, so doesn't have an inverse. However, if you restrict the domain to, say, x ≥ 0, then this restricted-domain function does have an inverse.

Alternatively, you could restrict the domain to x ≤ 0, and that function would have an inverse.
 
  • #3
Thanks for that!
 

FAQ: One-to-one functions and inverse functions.

What is a one-to-one function?

A one-to-one function is a type of mathematical function where each input has exactly one corresponding output. This means that no two inputs will have the same output. In other words, each input has a unique output.

How do you determine if a function is one-to-one?

To determine if a function is one-to-one, you can use the horizontal line test. Draw a horizontal line across the graph of the function. If the line intersects the graph in more than one point, then the function is not one-to-one. If the line only intersects the graph at one point, then the function is one-to-one.

What is an inverse function?

An inverse function is a function that "undoes" the original function. It is the reverse operation of the original function. In other words, if you input the output of the original function into the inverse function, you will get the original input value back.

How do you find the inverse of a one-to-one function?

To find the inverse of a one-to-one function, you can switch the positions of the input and output variables and solve for the new output variable. This new function will be the inverse of the original function. It is also important to note that the domain and range of the original function will be switched in the inverse function.

Can a function have more than one inverse?

No, a function can only have one inverse. This is because the inverse function must "undo" the original function, and if there are multiple possible outputs for a given input, the inverse function would not be able to determine which input to return. In other words, a function can only have one inverse that satisfies the definition of an inverse function.

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