Problem

Find the linear approximation of $f(x)=\sqrt[3]{x}$ when $x=8$.

Answer

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Answer

\(\boxed{L(x) = 2 + \frac{1}{12}(x - 8)}\) is the linear approximation of \(f(x) = x^{1/3}\) at \(x = 8\).

Steps

Step 1 :Find the derivative of the function \(f(x) = x^{1/3}\). The derivative is \(f'(x) = \frac{1}{3}x^{-2/3}\).

Step 2 :Evaluate \(f(8)\) and \(f'(8)\). We find that \(f(8) = 2\) and \(f'(8) = \frac{1}{12}\).

Step 3 :Write the equation of the tangent line using the formula \(L(x) = f(a) + f'(a)(x - a)\). Substituting the values we found, we get \(L(x) = 2 + \frac{1}{12}(x - 8)\).

Step 4 :\(\boxed{L(x) = 2 + \frac{1}{12}(x - 8)}\) is the linear approximation of \(f(x) = x^{1/3}\) at \(x = 8\).

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