derivative of (2x^2-3/(x^2+1))

解

\frac{d}{d x} (\frac{2 x ^{2} - 3}{x ^{2} + 1})

\frac{10 x}{( x ^{2} + 1 ) ^{2}}

解答ステップ

\frac{d}{d x} (\frac{2 x ^{2} - 3}{x ^{2} + 1})

商の法則を適用:

(\frac{f}{g})^{'} = \frac{f ^{'} \cdot g - g ^{'} \cdot f}{g ^{2}}

= \frac{\frac{d}{d x} ( 2 x ^{2} - 3 ) ( x ^{2} + 1 ) - \frac{d}{d x} ( x ^{2} + 1 ) ( 2 x ^{2} - 3 )}{( x ^{2} + 1 ) ^{2}}

\frac{d}{d x} (2 x^{2} - 3) = 4 x

\frac{d}{d x} (x^{2} + 1) = 2 x

= \frac{4 x ( x ^{2} + 1 ) - 2 x ( 2 x ^{2} - 3 )}{( x ^{2} + 1 ) ^{2}}

拡張

4 x (x^{2} + 1) - 2 x (2 x^{2} - 3) : 10 x

= \frac{10 x}{( x ^{2} + 1 ) ^{2}}