(\partial)/(\partial x)(cos(2cx+act))

解

\frac{\partial}{\partial x} (cos (2 c x + a c t))

- sin (2 c x + a c t) \cdot 2 c

解答ステップ

\frac{\partial}{\partial x} (cos (2 c x + a c t))

c, a, t

を定数として扱う

連鎖法則を適用:

- sin (2 c x + a c t) \frac{\partial}{\partial x} (2 c x + a c t)

= - sin (2 c x + a c t) \frac{\partial}{\partial x} (2 c x + a c t)

\frac{\partial}{\partial x} (2 c x + a c t) = 2 c

= - sin (2 c x + a c t) \cdot 2 c