Answer:
[tex]f^{-1}(x)=\pm \sqrt{x-7}[/tex]
Step-by-step explanation:
Given [tex]f(x)=x^2+7[/tex]
Let
[tex]y=x^2+7[/tex]
Interchange x and y
[tex]x=y^2+7[/tex]
Solve for y.
[tex]x-7=y^2[/tex]
Take square root of both sides.
[tex]y=\pm \sqrt{x-7}[/tex]
Hence the inverse of the given function is;
[tex]f^{-1}(x)=\pm \sqrt{x-7}[/tex]
Third choice is correct.
