derivative of (x+2/(x^2-4))

解

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

- \frac{1}{( x - 2 ) ^{2}}

解答ステップ

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

商の法則を適用:

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

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

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

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

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

簡素化

\frac{1 \cdot ( x ^{2} - 4 ) - 2 x ( x + 2 )}{( x ^{2} - 4 ) ^{2}} : - \frac{1}{( x - 2 ) ^{2}}

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