Question

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

Answer 1

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

$2y^{2}=x+8$

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

so

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

therefore

the answer is

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

Answer 2

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

$y = \sqrt{ \frac{x+8}{2} }$