Problem

If $f$ is one-to-one, find an equation for its inverse. \[ f(x)=4 x^{3}-3 \] A. $f^{-1}(x)=\sqrt[3]{\frac{x}{4}}+3$ B. $f^{-1}(x)=\sqrt[3]{\frac{x+3}{4}}$ C. $f^{-1}(x)=\sqrt[3]{\frac{x-3}{4}}$ D. The function is not one-to-one.

Solution

Step 1 :To find the inverse of the function \(f(x)=4x^3-3\), we first replace \(f(x)\) with \(y\), so the equation becomes \(y=4x^3-3\).

Step 2 :Next, we swap \(x\) and \(y\) to get \(x=4y^3-3\).

Step 3 :Then, we solve for \(y\) to get the inverse function. Add 3 to both sides to get \(x+3=4y^3\).

Step 4 :Divide both sides by 4 to get \(\frac{x+3}{4}=y^3\).

Step 5 :Finally, take the cube root of both sides to get \(y=\sqrt[3]{\frac{x+3}{4}}\).

Step 6 :So, the inverse function is \(f^{-1}(x)=\sqrt[3]{\frac{x+3}{4}}\), which corresponds to option B.

From Solvely APP
Source: https://solvelyapp.com/problems/19047/

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