Question

Which equation is the inverse of y = 2x2 – 8?

Answer 1

x=2y^2 -8
or
2y^2= x+8
y^2 = (x+8)/2


`y = \sqrt{ (x+8)/(2) }`

Answer 2

we have

`y=2x^(2) -8`

Step
`1`

Exchanges the variable x for y and the variable y for x

`x=2y^(2) -8`

Step
`2`

Clear the variable y

`2y^(2)=x+8`

`y^(2)=(x+8)/(2) \\ \\y=(+/-)\sqrt{(x+8)/(2)}`

so

the inverse is equal to------->
`y=(+/-)\sqrt{(x+8)/(2)}`

therefore

the answer is

`y=(+/-)\sqrt{(x+8)/(2)}`