Find Explicit Expression for f^-1(x) in f(x)=\frac{-2x}{3x-4}

In summary, to determine if the given function f(x)=\frac{-2x}{3x-4} is invertible, we need to check if it is one-one and onto. If it is, then f^-1 is a function that exists. To find an explicit expression for f^-1, we can let y=\frac{-2x}{3x-4} and swap x and y, then solve for y. This will give us the explicit expression for f^-1(x).
  • #1
needhelp83
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For the function f given by the equation f(x)=[tex]\frac{-2x}{3x-4}[/tex], determine where the relation f^-1 is a function. If f^-1 is a function, write an explicit expression for f^-1(x).

Need help writing explicit expression. Any guidance?
 
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  • #2
You have to check if the given function is invertible or not.If it is one-one and onto then it is invertible and f^-1 is a function or it exists.
I don't get you , when you say 'explicit function'.You mean the inverse?
 
  • #3
You first say "determine where the relation f-1 is a function" which implies that f-1 is a function for some values of x, not others. But then you say "If f-1 is a function". Are you sure it wasn't "determine whether the relation f-1 is a function?

Let [itex]y= \frac{-2x}{3x-4}[/itex] and "swap" x and y:
[tex]x= \frac{-2y}{3y-4}[/itex]
Now can you solve that for y? If so, f-1 exists and you have found it.
 

FAQ: Find Explicit Expression for f^-1(x) in f(x)=\frac{-2x}{3x-4}

What is the inverse function of f(x)?

The inverse function of f(x) is denoted as f-1(x) and it represents the operation that undoes the original function. In this case, f-1(x) is the inverse of f(x) = -2x3x - 4.

How do you find the explicit expression for f-1(x)?

To find the explicit expression for f-1(x), we follow these steps:
1. Replace f(x) with y.
2. Solve the equation for x in terms of y.
3. Interchange x and y.
4. Replace y with f-1(x).

What is the domain and range of f-1(x)?

The domain of f-1(x) is the range of f(x), and the range of f-1(x) is the domain of f(x). In this case, the domain of f-1(x) is all real numbers except 4/3, and the range is all real numbers.

How do you verify if f-1(x) is the actual inverse of f(x)?

To verify if f-1(x) is the actual inverse of f(x), we can use the composition of functions method. We substitute f(x) into f-1(x) and simplify the expression. If the result is x, then f-1(x) is the inverse of f(x).

Can f-1(x) be graphed on the same coordinate plane as f(x)?

Yes, f-1(x) can be graphed on the same coordinate plane as f(x). The graph of f-1(x) is the reflection of the graph of f(x) over the line y = x. This means that the points (x, y) on the graph of f(x) will become (y, x) on the graph of f-1(x).

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