derivative of (4x/(x+3))

解

\frac{d}{d x} (\frac{4 x}{x + 3})

\frac{12}{( x + 3 ) ^{2}}

解答ステップ

\frac{d}{d x} (\frac{4 x}{x + 3})

定数を除去:

(a \cdot f)^{'} = a \cdot f^{'}

= 4 \frac{d}{d x} (\frac{x}{x + 3})

商の法則を適用:

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

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

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

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

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

簡素化

4 \cdot \frac{1 \cdot ( x + 3 ) - 1 \cdot x}{( x + 3 ) ^{2}} : \frac{12}{( x + 3 ) ^{2}}

= \frac{12}{( x + 3 ) ^{2}}