(\partial)/(\partial x)(-3ycos(-9x))

解答

\frac{\partial}{\partial x} (- 3 y cos (- 9 x))

27 y sin (9 x)

求解步骤

\frac{\partial}{\partial x} (- 3 y cos (- 9 x))

化简

- 3 y cos (- 9 x) : - 3 y cos (9 x)

= \frac{\partial}{\partial x} (- 3 y cos (9 x))

将

y

视为常数

将常数提出:

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

= - 3 y \frac{\partial}{\partial x} (cos (9 x))

使用连锁律:

- sin (9 x) \frac{\partial}{\partial x} (9 x)

= - sin (9 x) \frac{\partial}{\partial x} (9 x)

\frac{\partial}{\partial x} (9 x) = 9

= - 3 y (- sin (9 x) \cdot 9)

化简

= 27 y sin (9 x)

\frac{d}{d x} (\frac{2}{4 x + 1})

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d er i v a t i v e 4 x e^{- k x}

\frac{\partial}{\partial x} (2 x y z^{2} - 192)

\int \frac{1}{ln ( x )} d x