📝 题目
例 4 求 $\displaystyle{\int \frac{\mathrm{d}x}{{x}^{2} - {a}^{2}}}$ .
💡 答案与解析
解 $\displaystyle \int \frac{\mathrm{d}x}{{x}^{2} - {a}^{2}} = \int \frac{\mathrm{d}x}{\left( {x - a}\right) \left( {x + a}\right) }$
$$ = \frac{1}{2a}\ln \left| \frac{x - a}{x + a}\right| + C. $$