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43 votes
43 votes
If f(x) =
√(x) +3 , what is the equation for f–1(x)?

User Dominykas Mostauskis
by
3.0k points

1 Answer

24 votes
24 votes

Answer:
f^(-1)(x) = (x-3)^2

Explanation:

We are given that
f(x) = √(x) + 3. A trick to solve for the inverse is to switch the f(x) and x in the equation. This gives us


x = √(f(x)) + 3

Now, we can solve for this f(x) which gives us


x = √(f(x)) + 3\\x -3 = √(f(x))\\(x -3)^2 = f(x)

Then we simply let that
f(x) be
f^(-1)(x). Thus, we have
f^(-1)(x) = (x-3)^2

User Yogesh Funde
by
2.9k points