Answered

Which equation is the inverse of [tex]\( y = 2x^2 - 8 \)[/tex]?

A. [tex]\( y = \pm \sqrt{\frac{x+8}{2}} \)[/tex]

B. [tex]\( y = \frac{\pm \sqrt{x+8}}{2} \)[/tex]

C. [tex]\( y = \pm \sqrt{\frac{x}{2} + 8} \)[/tex]

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



Answer :

Let's find the inverse of the function [tex]\( y = 2x^2 - 8 \)[/tex] step by step.

1. Start with the given equation:

[tex]\[ y = 2x^2 - 8 \][/tex]

2. Solve for [tex]\( x \)[/tex] in terms of [tex]\( y \)[/tex]:

First, add 8 to both sides to isolate the [tex]\( x^2 \)[/tex] term:

[tex]\[ y + 8 = 2x^2 \][/tex]

Next, divide both sides by 2:

[tex]\[ \frac{y + 8}{2} = x^2 \][/tex]

Now, take the square root of both sides. Remember to account for both the positive and negative roots:

[tex]\[ x = \pm \sqrt{\frac{y + 8}{2}} \][/tex]

3. Interchange [tex]\( x \)[/tex] and [tex]\( y \)[/tex] to find the inverse function:

[tex]\[ y = \pm \sqrt{\frac{x + 8}{2}} \][/tex]

4. Check the given options:

Let's compare our result with the options given:

- Option 1: [tex]\( y = \pm \sqrt{\frac{x + 8}{2}} \)[/tex]
- Option 2: [tex]\( y = \frac{\pm \sqrt{x + 8}}{2} \)[/tex]
- Option 3: [tex]\( y = \pm \sqrt{\frac{x}{2} + 8} \)[/tex]
- Option 4: [tex]\( y = \frac{\pm \sqrt{x}}{2} + 4 \)[/tex]

We see that our derived inverse function matches exactly with Option 1:

[tex]\[ y = \pm \sqrt{\frac{x + 8}{2}} \][/tex]

So, the correct inverse equation is:

[tex]\[ y = \pm \sqrt{\frac{x + 8}{2}} \][/tex]