derivative (sqrt(x))/(9+x)

解

導関数

\frac{x}{9 + x}

\frac{9 - x}{2 x ( 9 + x ) ^{2}}

解答ステップ

\frac{d}{d x} (\frac{x}{9 + x})

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 ) ( 9 + x ) - \frac{d}{d x} ( 9 + x ) x}{( 9 + x ) ^{2}}

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

\frac{d}{d x} (9 + x) = 1

= \frac{\frac{1}{2 x} ( 9 + x ) - 1 \cdot x}{( 9 + x ) ^{2}}

簡素化

\frac{\frac{1}{2 x} ( 9 + x ) - 1 \cdot x}{( 9 + x ) ^{2}} : \frac{9 - x}{2 x ( 9 + x ) ^{2}}

= \frac{9 - x}{2 x ( 9 + x ) ^{2}}