Answer:
a
Step-by-step explanation:
To obtain the inverse, rearrange the relation making x the subject
y = x² + 4 ( subtract 4 from both sides )
y - 4 = x² , or
x² = y - 4 ( take square root of both sides )
x = ± [tex]\sqrt{y-4}[/tex]
Change y into terms of x with x = [tex]f^{-1}[/tex] (x) , that is
[tex]f^{-1}[/tex] (x) = ± [tex]\sqrt{x-4}[/tex] → a
