Answer: B
Step-by-step explanation:
To find the inverse function, you switch x with y and y with x. Then, you solve for y.
[switch x with y, and y with x]
[add both sides by 4]
[square root both sides]
[add both sides by 1]
Now that we know the inverse function, we can actually tell that the answer is B. We know this because of the restriction that f(x) is x≤1. This makes it positive, and B the answer.