Solution
We have the following integral:
[tex]\int \frac{2x}{(4+3x^{2})^{2}}dx[/tex]
We can use the substitution u= 4 +3x² and we have du= 6x dx, then we have this:
[tex]\int \frac{2x}{(u^{})^2}\cdot\frac{du}{6x}=\frac{1}{3}\int u^{-2}du=\frac{1}{3}\cdot\frac{u^{-1}}{-1}+C=-\frac{1}{3u}+C=-\frac{1}{3(4+3x^{2})}+C[/tex]
