Answer:
[tex]\mathrm{A.} \: y=\± \sqrt {x+4}[/tex]
Step-by-step explanation:
[tex]y = x^2 - 4[/tex]
Add 4 to both sides.
[tex]y + 4 = x^2[/tex]
Take the square root on both sides.
[tex]\± \sqrt{y+4} =x[/tex]
Switch variables.
[tex]\± \sqrt {x+4} =y[/tex]
