<s>[INST] How to solve $\int_{-1}^{1} (x^{4/3} + 4x^{1/3}) dx$? I started by integrating it this way:
$$(\frac{3}{7} x^{7/3} + \frac{16}{4}x^{4/3})$$
What is wrong with it?
 [/INST] You are asking "What is wrong with it?"
$$(\frac{3}{7} x^{7/3} + \frac{16}{4}x^{4/3})$$
Check the derivative
$$(\frac{3}{7}\frac{7}{3} x^{4/3} + \color{red}{\frac{16}{4}\frac{4}{3}}x^{1/3}).$$
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