Tính đạo hàm cấp hai của \(y=\dfrac{x^2}{1-x}\) .
\(-\dfrac{4}{\left(1-x\right)^3}\).\(-\dfrac{2}{\left(1-x\right)^3}\).\(\dfrac{2}{\left(1-x\right)^3}\).\(\dfrac{2}{\left(1-x\right)^5}\).Hướng dẫn giải:\(y=\dfrac{x^2}{1-x}=-\dfrac{x^2}{x-1}=-\dfrac{x^2-1+1}{x-1}=-\left(x+1\right)-\left(x-1\right)^{-1}\Rightarrow y'=-1-\left(-1\right)\left(x-1\right)^{-2}\Rightarrow y"=-\left(-1\right)\left(-2\right)\left(x-1\right)^{-3}=-\dfrac{2}{\left(x-1\right)^3}=\dfrac{2}{\left(1-x\right)^3}\)