(\partial)/(\partial y)(cos(x+4y))

解答

\frac{\partial}{\partial y} (cos (x + 4 y))

- sin (x + 4 y) \cdot 4

求解步骤

\frac{\partial}{\partial y} (cos (x + 4 y))

将

x

视为常数

使用连锁律:

- sin (x + 4 y) \frac{\partial}{\partial y} (x + 4 y)

= - sin (x + 4 y) \frac{\partial}{\partial y} (x + 4 y)

\frac{\partial}{\partial y} (x + 4 y) = 4

= - sin (x + 4 y) \cdot 4