формулы:[r] [m]\int\frac{du}{u}=ln|u|+C; \int\frac{dx}{x^2+a^2}=\frac{1}{a}arctg\frac{x}{a}+C[/m]; [/r]
[m]a^2=\frac{2}{5}[/m]
[m]=\frac{1}{5}\cdot ln |x^2+\frac{2}{5}|+\frac{1}{5}\cdot 3\cdot \frac{1}{\sqrt{\frac{2}{5}}} arctg \frac{x}{\sqrt{\frac{2}{5}}}+C=[/m]
[m]=\frac{1}{5}\cdot ln |x^2+\frac{2}{5}|+\frac{3\sqrt{5}}{5\sqrt{2}}arctg \frac{x\sqrt{5}}{\sqrt{2}}+C[/m]