Find the inverse of the function.

[tex]\[ y = 2x^2 - 4 \][/tex]

A. \( y = \pm \sqrt{x} + 2 \)
B. \( y = \pm \sqrt{\frac{x + 4}{2}} \)
C. \( y = \pm \frac{\sqrt{x + 4}}{2} \)
D. [tex]\( y = \pm \sqrt{x} - 2 \)[/tex]



Answer :

To find the inverse of the function \( y = 2x^2 - 4 \), follow these steps:

1. Start with the given function:
[tex]\[ y = 2x^2 - 4 \][/tex]

2. Swap \(y\) and \(x\): To find the inverse, we interchange the roles of \(x\) and \(y\).
[tex]\[ x = 2y^2 - 4 \][/tex]

3. Solve for \(y\): We need to isolate \(y\) in terms of \(x\).

- First, add 4 to both sides to start isolating \(y^2\):
[tex]\[ x + 4 = 2y^2 \][/tex]

- Next, divide both sides by 2 to further isolate \(y^2\):
[tex]\[ \frac{x + 4}{2} = y^2 \][/tex]

- Finally, take the square root of both sides to solve for \(y\):
[tex]\[ y = \pm \sqrt{\frac{x + 4}{2}} \][/tex]

4. State the inverse functions:
The resulting expressions represent the inverse functions of the given original function. Therefore, we have:
[tex]\[ y = \pm \sqrt{\frac{x + 4}{2}} \][/tex]
And equivalently, since taking the square root of a fraction is the same as taking the square root of the numerator and denominator separately:
[tex]\[ y = \pm \frac{\sqrt{x + 4}}{2} \][/tex]

Thus, the inverse functions of the original function \( y = 2x^2 - 4 \) are:
[tex]\[ y = \pm \sqrt{\frac{x + 4}{2}} \][/tex]
or equivalently:
[tex]\[ y = \pm \frac{\sqrt{x + 4}}{2} \][/tex]

So, the correct answer is:
[tex]\[ y = \pm \sqrt{\frac{x+4}{2}} \][/tex]
or
[tex]\[ y = \pm \frac{\sqrt{x+4}}{2} \][/tex]

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