4. \( \int (x^2 - 2)\sqrt{x} \, dx = \)






Answer is: option3

\( \frac{2}{7}x^3\sqrt{x} - \frac{4}{3}x\sqrt{x} + C \)

Solution:

\[ (x^2 - 2)\sqrt{x} = x^2\sqrt{x} - 2\sqrt{x} \]

Recall: \( \sqrt{x} = x^{1/2} \), so:

  1. \( x^2\sqrt{x} = x^{2 + 1/2} = x^{5/2} \)
  2. \( 2\sqrt{x} = 2x^{1/2} \)

So the integral becomes:

\[ \int (x^{5/2} - 2x^{1/2}) \, dx \]

\[ \int x^{5/2} \, dx = \frac{x^{7/2}}{7/2} = \frac{2}{7}x^{7/2} \]

\[ \int 2x^{1/2} \, dx = 2 \cdot \frac{x^{3/2}}{3/2} = \frac{4}{3}x^{3/2} \]

\[ \int (x^2 - 2)\sqrt{x} \, dx = \frac{2}{7}x^{7/2} - \frac{4}{3}x^{3/2} + C \]

  1. \( x^{7/2} = x^3\sqrt{x} \)
  2. \( x^{3/2} = x\sqrt{x} \)

So the final answer is: (C)

\[ \frac{2}{7}x^3\sqrt{x} - \frac{4}{3}x\sqrt{x} + C \]

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