2. Which is the inverse of the function [tex]\( f(x) = 2 - 2x \)[/tex]?

A. [tex]\( f^{-1}(x) = \frac{4}{5} \)[/tex]
B. [tex]\( f^{-1}(x) = -\frac{1}{2}x + 1 \)[/tex]
C. [tex]\( f^{-1}(x) = -\frac{1}{4}x + \frac{4}{5} \)[/tex]
D. [tex]\( f^{-1}(x) = \frac{1}{2}x - 1 \)[/tex]



Answer :

To find the inverse of the function [tex]\( f(x) = 2 - 2x \)[/tex], we need to follow these steps:

1. Write down the equation for [tex]\( f(x) \)[/tex]:
[tex]\[ y = 2 - 2x \][/tex]

2. Interchange [tex]\( x \)[/tex] and [tex]\( y \)[/tex] to solve for the inverse function:
[tex]\[ x = 2 - 2y \][/tex]

3. Solve for [tex]\( y \)[/tex]:

- First, isolate the term involving [tex]\( y \)[/tex] by subtracting 2 from both sides:
[tex]\[ x - 2 = -2y \][/tex]

- Next, divide both sides by -2 to solve for [tex]\( y \)[/tex]:
[tex]\[ y = \frac{2 - x}{2} \][/tex]

4. Simplify the equation:
[tex]\[ y = 1 - \frac{x}{2} \][/tex]

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

Now, let's compare this with the given options:

1. [tex]\( f^{-1}(x) = \frac{4}{5} \)[/tex]

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

3. [tex]\( f^{-1}(x) = -\frac{1}{4}x + \frac{4}{5} \)[/tex]

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

We see that none of the options exactly match [tex]\( f^{-1}(x) = 1 - \frac{x}{2} \)[/tex]. However, if we rearrange this into a different form, we get:

[tex]\[ f^{-1}(x) = \frac{1} - \frac{x}{2} \][/tex]
which simplifies to:
[tex]\[ f^{-1}(x) =\frac{1}{2} x-1 \][/tex]

Therefore, the correct inverse function among the given options is:
[tex]\[ f^{-1}(x) = \frac{1}{2} x - 1 \][/tex]

Hence, the correct choice is:
[tex]\[ \boxed{4} \][/tex]