I need help asap please

Question

Consider the function f(x)=−x2+6 on the domain [0,∞).

Use the range of f(x) to determine the domain of f−1(x).

What is the domain of f−1(x)?

Answers:

−∞<x≤6

−∞<f−1(x)≤6

6<x<∞

−6<f−1(x)<6

−6<x<6

6<f−1(x)<∞

Answer 1

y = -x^2 + 6

x = -y^2 + 6

x - 6 = -y^2

6 - x = y^2

+or- sqrt( 6 - x) = y

the domain of the inverse is 6-x>0

6 > x

x<6

(-infinity,6)