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Question
Let f: R → R be the functions defined by f(x) = x3 + 5. Then f–1(x) is ______.
Options
`(x + 5)^(1/3)`
`(x - 5)^(1/3)`
`(5 - x)^(1/3)`
5 – x
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Solution
Let f: R → R be the functions defined by f(x) = x3 + 5. Then f–1(x) is `(x - 5)^(1/3)`.
Explanation:
We have, f(x) = x3 + 5 = y ....(Let)
⇒ y = x3 + 5
⇒ x3 = y – 5
⇒ x = `(y - 5)^(1/3)`
⇒ f–1(x) = `(x - 5)^(1/3)`
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