12222

$$\frac{{ - b \pm \sqrt {{b^2} - 4ac} }}{{2a}}$$

$$frac{{ - b pm sqrt {{b^2} - 4ac} }}{{2a}}$$

555555555 发表于 2016-7-7 14:58

[tex=null]\int_{a}^{b} = \frac{34}{56} + \sqrt{234}[/tex]