$$ \begin{array}{l}{x}\\ {1}\\ {\left( {\frac{u }{v } } \right)=} \\ {f'(x)=\frac{2\left( {x-3 } \right) - \left( {2x } \right)}{\left( {x-3 } \right)^2 }=\frac{2x-6-2x }{\left( { x-3 } \right)^2}} \\ {\text{donc }f'(x) = \frac{-6 }{\left( {x-3 } \right)^2 } } \end{array} \left[{a}\right] u^2 \ne \le = \ge \text{abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ() .éèêà} \times - + a^2 \int_{a}^{b} f'(t)dt \vec{u} \overrightarrow {AB} \overline {AB} \underline {AB} \widehat{BAC} \sin \cos \tan \ln \lim_{x \to { }} \left\| {a} \right\| \sum_{a}^{b} \prod{a}^{b} \lim_{x \to {a}} \begin{matrix}{a} & {b}\\{c} & {d}\end{matrix} \sqrt{\frac{x^2}{x+1}} \sqrt [3] {a} \acute{e} \grave{e} \grave{a} \grave{u} \hat{e} \hat{o} \hat{a} $$