(\partial)/(\partial p)((p+q)/(p+r))

解

\frac{\partial}{\partial p} (\frac{p + q}{p + r})

\frac{- q + r}{( p + r ) ^{2}}

解答ステップ

\frac{\partial}{\partial p} (\frac{p + q}{p + r})

q, r

を定数として扱う

商の法則を適用:

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

= \frac{\frac{\partial}{\partial p} ( p + q ) ( p + r ) - \frac{\partial}{\partial p} ( p + r ) ( p + q )}{( p + r ) ^{2}}

\frac{\partial}{\partial p} (p + q) = 1

\frac{\partial}{\partial p} (p + r) = 1

= \frac{1 \cdot ( p + r ) - 1 \cdot ( p + q )}{( p + r ) ^{2}}

簡素化

\frac{1 \cdot ( p + r ) - 1 \cdot ( p + q )}{( p + r ) ^{2}} : \frac{- q + r}{( p + r ) ^{2}}

= \frac{- q + r}{( p + r ) ^{2}}