y

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y= x2 + 5
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y2 = x - 5
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Determine if y=x2+5
and y2=x−5
are inverses of each other.

(1 point)
Responses

Yes, they are inverses because all corresponding ordered pairs are reflections of one another across the line y=x
.
Yes, they are inverses because all corresponding ordered pairs are reflections of one another across the line y equals x .

No, they are not inverses because all corresponding ordered pairs are reflections of one another across the line y=−x
.
No, they are not inverses because all corresponding ordered pairs are reflections of one another across the line y equals negative x .

Yes, they are inverses because all corresponding ordered pairs are reflections of one another across the line y=−x
.
Yes, they are inverses because all corresponding ordered pairs are reflections of one another across the line y equals negative x .

No, they are not inverses because all corresponding ordered pairs are reflections of one another across the line y=x
.
No, they are not inverses because all corresponding ordered pairs are reflections of one another across the line y equals x .

1 answer

To determine if the two given functions \( y = x^2 + 5 \) and \( y_2 = x - 5 \) are inverses of each other, we need to check if the output of one function can be transformed back to the original input of the other function.

  1. Finding the inverse of \( y = x^2 + 5 \):

    • Start with \( y = x^2 + 5 \)
    • Solve for \( x \): \[ y - 5 = x^2 \ x = \sqrt{y - 5} \text{ or } x = -\sqrt{y - 5} \]

    The inverse is not a single function; it's two parts due to the square root.

  2. Finding the output of the second function \( y_2 = x - 5 \): To check if they are true inverses of one another, we would plug \( y_2 \) into \( y \):

    Substitute \( x = y_2 + 5 \) into \( y = x^2 + 5 \):

    \[ y = (y_2 + 5)^2 + 5 \]

    Expanding this yields: \[ y = (x - 5 + 5)^2 + 5 \ y = (x)^2 + 5 \ y = x^2 + 5 \]

    This shows that \( y_2 = x - 5 \) is not the output or input necessary to return to \( x \).

  3. Therefore, checking if the ordered pairs are reflections across the line \( y = x \): To check if they are reflections of each other across the line \( y = x \), you should swap \( x \) and \( y \) in both functions.

The reflections do not yield the same outputs for the inputs, indicating that they do not serve as true inverses.

Final Conclusion:

The correct response is: No, they are not inverses because all corresponding ordered pairs are reflections of one another across the line \( y = x \).