(\partial)/(\partial x)(1/(|x|))

解答

\frac{\partial}{\partial x} (\frac{1}{∣ x ∣})

- \frac{1}{x ∣ x ∣}

求解步骤

\frac{\partial}{\partial x} (\frac{1}{∣ x ∣})

使用指数法则:

\frac{1}{a} = a^{- 1}

= \frac{\partial}{\partial x} (∣ x ∣^{- 1})

使用连锁律:

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

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

\frac{\partial}{\partial x} (∣ x ∣) = \frac{x}{∣ x ∣}

= - \frac{1}{∣ x ∣ ^{2}} \cdot \frac{x}{∣ x ∣}

化简

- \frac{1}{∣ x ∣ ^{2}} \cdot \frac{x}{∣ x ∣} : - \frac{1}{x ∣ x ∣}

= - \frac{1}{x ∣ x ∣}

\int_{0}^{2} 2 x + 5 d x

\frac{d}{d x} (40 x (5 x^{2} - 8))

\int_{2}^{\infty} \frac{1}{x ^{5}} d x

\int x e^{\frac{x ^{2}}{2}} d x

x \to π lim (3 arctan (x))