Problem

If $\mathrm{f}$ is one-to-one, find an equation for its inverse.
\[
f(x)=x^{3}-6
\]
A. $f^{-1}(x)=\sqrt[3]{x-6}$
B. $f^{-1}(x)=\sqrt[3]{x}+6$
C. $f^{-1}(x)=\sqrt[3]{x+6}$
D. The function is not one-to-one.

Answer

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Answer

Comparing this with the options given, we find that the correct answer is \(\boxed{\text{C. } f^{-1}(x)=\sqrt[3]{x+6}}\).

Steps

Step 1 :Given that the function \(f(x)=x^{3}-6\) is one-to-one, we can find its inverse by swapping \(x\) and \(y\) and solving for \(y\).

Step 2 :So, we have \(x=y^{3}-6\).

Step 3 :Adding 6 to both sides, we get \(x+6=y^{3}\).

Step 4 :Taking the cube root of both sides, we get \(y=\sqrt[3]{x+6}\).

Step 5 :So, the inverse function \(f^{-1}(x)=\sqrt[3]{x+6}\).

Step 6 :Comparing this with the options given, we find that the correct answer is \(\boxed{\text{C. } f^{-1}(x)=\sqrt[3]{x+6}}\).

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