4) Integration of reducible and irreducible quadratic factors:

• A reducible quadratic factor can be factored into linear factors and then integrated using standard integration rules.
• An irreducible quadratic factor cannot be factored and requires a special rule for integration.
• For example, the integral of 1/(x^2 + a^2) is (1/a) arctan(x/a).

Important Formulas to Remember in these topic

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$$\int \frac{Ax + B}{(ax^2 + bx + c)^n}dx$$

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