Answer:
[tex]f^{-1}(x)= x^2 + 5 \,,\,\,x\geq 0[/tex]
Step-by-step explanation:
Use the method of swapping x and y and isolating y.
[tex]f(x) = y = \sqrt{x-5}\,,\,\,\,x\geq 5,y\geq0\\\\f^{-1}:x=\sqrt{y-5}\,,\,\,\,y\geq 5, x\geq 0\\x^2 = y-5\\y = x^2 + 5 = f^{-1}(x)\\[/tex]
Note that domain/range will be swapped as well.