Find the inverse of the function.

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

A. [tex]\[ y = \pm \sqrt{x} + 2 \][/tex]

B. [tex]\[ y = \pm \sqrt{\frac{x + 4}{2}} \][/tex]

C. [tex]\[ y = \pm \frac{\sqrt{x + 4}}{2} \][/tex]

D. [tex]\[ y = \pm \sqrt{x} - 2 \][/tex]



Answer :

To find the inverse of the function [tex]\( y = 2x^2 - 4 \)[/tex], we need to follow several steps.

1. Swap [tex]\( x \)[/tex] and [tex]\( y \)[/tex]:
The given equation is:
[tex]\[ y = 2x^2 - 4 \][/tex]
To find the inverse, we swap [tex]\( y \)[/tex] and [tex]\( x \)[/tex]:
[tex]\[ x = 2y^2 - 4 \][/tex]

2. Solve for [tex]\( y \)[/tex]:
Now, we need to isolate [tex]\( y \)[/tex]:

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

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

- Finally, take the square root of both sides. Remember to consider both the positive and negative roots:
[tex]\[ y = \pm \sqrt{\frac{x + 4}{2}} \][/tex]

3. Write the inverse function:
The inverse function can be expressed as:
[tex]\[ y = \pm \sqrt{\frac{x + 4}{2}} \][/tex]

Therefore, the inverse of the function [tex]\( y = 2x^2 - 4 \)[/tex] is:
[tex]\[ y = \pm \sqrt{\frac{x + 4}{2}} \][/tex]

From the given choices, this corresponds to:
[tex]\[ y = \pm \sqrt{\frac{x+4}{2}} \][/tex]