Patrick T. answered 01/23/23
Tutor Specializing in French & Math (up to college Pre-Calculus)
Hello Anika, I sincerely apologize, I had it wrong previously. Please find the edited version here.
1st: the domain of f(x) is (-∞, 3]; the range of f(x) is [0, ∞). Keep in mind:
The domain of the inverse = range of original function, so domain of f-1(y) = [0, ∞).
Range of inverse = domain of original function = (-∞, 3]
----
Now, to find that inverse, you would replace f(x) by y and get: y = (x-3)2
Next, you'd need to solve for x. You could square root both sides of the previous equation and get:
±√y = x - 3
Add 3 to both sides and you get f-1 (y) = x = 3 ±√y
However, your answer has to be one of 3 +√y or 3 -√y. Which of those two potential inverse functions have a domain of [0, ∞) and a range of (-∞, 3]
Both have [0, ∞) as domain but only 3 -√y has a range of (-∞,3], so the final answer is f −1(y) = 3 - √y