Tính đạo hàm của hàm số sau: $y = {x^4} - 3{x^2} + 2x - 1$

$- \dfrac{3}{{{{\left( {x + 2} \right)}^2}}}$             

$\dfrac{3}{{x + 2}}$ 

$\dfrac{3}{{{{\left( {x + 2} \right)}^2}}}$ 

$\dfrac{2}{{{{\left( {x + 2} \right)}^2}}}$

$\dfrac{1}{6}$ 

$\dfrac{1}{{12}}$ 

$- \dfrac{1}{6}$ 

$- \dfrac{1}{{12}}$

$\{1\}$

$\mathbb{R}\backslash \left\{ 1 \right\}$

$\emptyset$ 

$R$

$y = \dfrac{{{x^3} + 1}}{x}$ 

$y = \dfrac{{3\left( {{x^2} + x} \right)}}{{{x^3}}}$ 

$y = \dfrac{{{x^3} + 5x - 1}}{x}$ 

$y = \dfrac{{2{x^2} + x - 1}}{x}$ 

$y'=- \dfrac{3}{{{x^4}}} + \dfrac{1}{{{x^3}}}$

$y'=\dfrac{{ - 3}}{{{x^4}}} + \dfrac{2}{{{x^3}}}$ 

$y'=\dfrac{{ - 3}}{{{x^4}}} - \dfrac{2}{{{x^3}}}$         

$y'=\dfrac{3}{{{x^4}}} - \dfrac{1}{{{x^3}}}$

$\dfrac{a}{c}$ 

$\dfrac{{ad - bc}}{{{{\left( {cx + d} \right)}^2}}}$ 

$\dfrac{{ad + bc}}{{{{\left( {cx + d} \right)}^2}}}$                         

$\dfrac{{ad - bc}}{{cx + d}}$