Westonci.ca offers quick and accurate answers to your questions. Join our community and get the insights you need today. Explore a wealth of knowledge from professionals across various disciplines on our comprehensive Q&A platform. Explore comprehensive solutions to your questions from a wide range of professionals on our user-friendly platform.

If [tex]\( f(x) = 3x \)[/tex] and [tex]\( g(x) = \frac{1}{3}x \)[/tex], which expression could be used to verify that [tex]\( g(x) \)[/tex] is the inverse of [tex]\( f(x) \)[/tex]?

A. [tex]\( 3x \left( \frac{x}{3} \right) \)[/tex]

B. [tex]\( \left( \frac{1}{3}x \right)(3x) \)[/tex]

C. [tex]\( \frac{1}{3}(3x) \)[/tex]

D. [tex]\( \frac{1}{3} \left( \frac{1}{3}x \right) \)[/tex]


Sagot :

To determine if [tex]\( g(x) = \frac{1}{3}x \)[/tex] is indeed the inverse of [tex]\( f(x) = 3x \)[/tex], we need to verify the compositions [tex]\( g(f(x)) \)[/tex] and [tex]\( f(g(x)) \)[/tex]. Specifically, each composition should yield the identity function [tex]\( x \)[/tex].

### Step-by-Step Verification

#### 1. Verify [tex]\( f(g(x)) \)[/tex]

First, let's compute [tex]\( f(g(x)) \)[/tex]:
[tex]\[ f(g(x)) = f\left(\frac{1}{3}x\right) = 3 \left(\frac{1}{3}x\right) = \left(\frac{3}{3}\right)x = x \][/tex]
The expression [tex]\( \frac{1}{3}(3x) \)[/tex] verifies that [tex]\( f(g(x)) = x \)[/tex]. This matches the identity function, verifying [tex]\( g(x) \)[/tex] as the inverse of [tex]\( f(x) \)[/tex] in this case.

#### 2. Verify [tex]\( g(f(x)) \)[/tex]

Next, let's compute [tex]\( g(f(x)) \)[/tex]:
[tex]\[ g(f(x)) = g(3x) = \frac{1}{3}(3x) = \left(\frac{3}{3}\right)x = x \][/tex]
The expression [tex]\( g(3x) = \frac{1}{3}(3x) \)[/tex] also gives us [tex]\( x \)[/tex], satisfying the identity function, which verifies [tex]\( f(x) \)[/tex] as the inverse of [tex]\( g(x) \)[/tex].

### Summary of the Options Provided

Now we can evaluate the given expressions to see which ones confirm [tex]\( g(x) = f^{-1}(x) \)[/tex].

1. [tex]\( 3x \left( \frac{x}{3} \right) \)[/tex]:

[tex]\[ 3x \left( \frac{x}{3} \right) = 3x \cdot \frac{x}{3} = x^2 \][/tex]
This results in [tex]\( x^2 \)[/tex], not [tex]\( x \)[/tex]. Therefore, it is incorrect.

2. [tex]\( \frac{1}{3}x \cdot 3x \)[/tex]:

[tex]\[ \frac{1}{3}x \cdot 3x = \left(\frac{1}{3} \cdot 3\right)x^2 = x^2 \][/tex]
This also results in [tex]\( x^2 \)[/tex], not [tex]\( x \)[/tex]. Therefore, it is incorrect.

3. [tex]\( \frac{1}{3}(3x) \)[/tex]:

[tex]\[ \frac{1}{3}(3x) = \left(\frac{3}{3}\right)x = x \][/tex]
This results in [tex]\( x \)[/tex], confirming it as a valid check.

4. [tex]\( \frac{1}{3}\left(\frac{1}{3}x\right) \)[/tex]:

[tex]\[ \frac{1}{3}\left(\frac{1}{3}x\right) = \frac{1}{9}x \][/tex]
This results in [tex]\( \frac{1}{9} x \)[/tex], not [tex]\( x \)[/tex]. Therefore, it is incorrect.

### Conclusion

The correct expressions that verify [tex]\( g(x) \)[/tex] is the inverse of [tex]\( f(x) \)[/tex] are:
- [tex]\( \frac{1}{3}(3x) \)[/tex]
- [tex]\( \left(\frac{1}{3} x \right)(3 x) \)[/tex]

Thus, the correct options are the second and third expressions:
[tex]\[ \boxed{\left(\frac{1}{3}x\right)(3x), \frac{1}{3}(3x)} \][/tex]
We appreciate your time. Please come back anytime for the latest information and answers to your questions. Thanks for stopping by. We strive to provide the best answers for all your questions. See you again soon. Stay curious and keep coming back to Westonci.ca for answers to all your burning questions.