derivative f(x)= x/(x+4)

解

導関数

f (x) = \frac{x}{x + 4}

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

解答ステップ

\frac{d}{d x} (\frac{x}{x + 4})

商の法則を適用:

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

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

\frac{d x}{d x} = 1

\frac{d}{d x} (x + 4) = 1

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

1 \cdot (x + 4) - 1 \cdot x = 4

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