Select the statement that is correct about the inverse of g(x)=x/3−2

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Statement #1: The inverse is g−1(x)=3x+2
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Statement #2: The inverse is g−1(x)=3x+6
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Statement #3: The inverse is g−1(x)=−6x
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Statement #4: The inverse does not exist because the function is not one-to-one.

1 answer

To find the inverse of the function \( g(x) = \frac{x}{3} - 2 \), we first rewrite the equation in terms of \( y \):

  1. \( y = \frac{x}{3} - 2 \)

Next, we solve for \( x \) in terms of \( y \):

  1. Add 2 to both sides:
    \( y + 2 = \frac{x}{3} \)

  2. Multiply both sides by 3:
    \( x = 3(y + 2) \)

Now, we express \( x \) in terms of \( y \):

  1. \( x = 3y + 6 \)

Then, we express the inverse function \( g^{-1}(x) \):

  1. \( g^{-1}(x) = 3x + 6 \)

Now, we can analyze the statements:

  • Statement #1: The inverse is \( g^{-1}(x) = 3x + 2 \)

    • Incorrect.
  • Statement #2: The inverse is \( g^{-1}(x) = 3x + 6 \)

    • Correct.
  • Statement #3: The inverse is \( g^{-1}(x) = -6x \)

    • Incorrect.
  • Statement #4: The inverse does not exist because the function is not one-to-one.

    • Incorrect. The function \( g(x) = \frac{x}{3} - 2 \) is a linear function and is one-to-one.

The correct statement is Statement #2: The inverse is \( g^{-1}(x) = 3x + 6 \).