Please help! functions operations. explain please

Answer:
[tex]f^{-1}(x)=x^2-3[/tex]
Step-by-step explanation:
Given [tex]f(x)=\sqrt{x+3}[/tex]
Let [tex]y=\sqrt{x+3}[/tex]
Interchange x and y
[tex]x=\sqrt{y+3}[/tex]
Solve for y, by first squaring both sides
[tex]x^2=y+3[/tex]
[tex]x^2-3=y[/tex]
Hence
[tex]f^{-1}(x)=x^2-3[/tex]
The last choice is correct