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1, this problem seems to be a simple integral problem, and the specific integral is very verbose;

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2. The integral method of this problem involves:

A, variable replacement, see the first and second lines in the diagram below;

B, factorization, see the third line;

C, fractional decomposition, bottom four lines;

D, differential method, see lines 5 and 6;

E, matching method, see line 6;

F. See the last three lines for arc tangent operation of differential angle.

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2. The specific answer process is as follows. If you have any questions, please answer them.

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3. If you click to enlarge, the picture will be clearer.

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