14. For small values of h, the function \( h(x) = \sqrt[3]{8 + h} \) is best approximated by which of the following?






Answer is: option3

\( 2 + \frac{h}{12} \)

Solution:

Let:

\[ f(x) = \sqrt[3]{x} \]

We expand \( f(x) \) around \( x = 8 \), so we define:

\[ f(x) = x^{1/3} \]

The derivative is:

\[ f'(x) = \frac{1}{3} x^{-2/3} = \frac{1}{3\sqrt[3]{x^2}} \]

Evaluating at \( x = 8 \):

\[ f(8) = \sqrt[3]{8} = 2 \]

\[ f'(8) = \frac{1}{3\sqrt[3]{8^2}} = \frac{1}{3 \cdot 4} = \frac{1}{12} \]

Using the linear approximation:

\[ f(8 + h) \approx f(8) + f'(8) \cdot h \]

\[ \sqrt[3]{8 + h} \approx 2 + \frac{h}{12} \]

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