What is the inverse function of [tex][tex]$f(x)=\frac{x}{x-2}$[/tex][/tex]?

A. [tex]$f^{-1}(x)=\frac{2 x}{x-1}$[/tex]
B. [tex]$f^{-1}(x)=\frac{2 x}{x+1}$[/tex]
C. [tex][tex]$f^{-1}(x)=-\frac{2 x}{x-1}$[/tex][/tex]
D. [tex]$f^{-1}(x)=\frac{x-2}{x}$[/tex]



Answer :

To find the inverse function of [tex]\( f(x) = \frac{x}{x-2} \)[/tex], let's go through the steps in detail.

1. Start with the given function:
[tex]\[ f(x) = \frac{x}{x-2} \][/tex]

2. Replace [tex]\( f(x) \)[/tex] with [tex]\( y \)[/tex]:
[tex]\[ y = \frac{x}{x-2} \][/tex]

3. Swap [tex]\( x \)[/tex] and [tex]\( y \)[/tex] to find the inverse function:
[tex]\[ x = \frac{y}{y-2} \][/tex]

4. Cross-multiply to eliminate the fraction:
[tex]\[ x(y - 2) = y \][/tex]

5. Distribute [tex]\( x \)[/tex] on the left side of the equation:
[tex]\[ xy - 2x = y \][/tex]

6. Move all terms involving [tex]\( y \)[/tex] to one side:
[tex]\[ xy - y = 2x \][/tex]

7. Factor out [tex]\( y \)[/tex]:
[tex]\[ y(x - 1) = 2x \][/tex]

8. Solve for [tex]\( y \)[/tex]:
[tex]\[ y = \frac{2x}{x - 1} \][/tex]

So, the inverse function is:
[tex]\[ f^{-1}(x) = \frac{2x}{x-1} \][/tex]

To match this with the given options:

1. [tex]\( f^{-1}(x)=\frac{2x}{x-1} \)[/tex]
2. [tex]\( f^{-1}(x)=\frac{2x}{x+1} \)[/tex]
3. [tex]\( f^{-1}(x)=-\frac{2x}{x-1} \)[/tex]
4. [tex]\( f^{-1}(x)=\frac{x-2}{x} \)[/tex]

The correct choice is:
[tex]\[ f^{-1}(x)=\frac{2x}{x-1} \][/tex]

Thus, the answer is the first option.