d/(da)(4sin(3a)cos(3a))

解答

\frac{d}{d a} (4 sin (3 a) cos (3 a))

12 cos (6 a)

求解步骤

\frac{d}{d a} (4 sin (3 a) cos (3 a))

化简

4 sin (3 a) cos (3 a) : 2 sin (6 a)

= \frac{d}{d a} (2 sin (6 a))

将常数提出:

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

= 2 \frac{d}{d a} (sin (6 a))

使用连锁律:

cos (6 a) \frac{d}{d a} (6 a)

= cos (6 a) \frac{d}{d a} (6 a)

\frac{d}{d a} (6 a) = 6

= 2 cos (6 a) \cdot 6

化简

= 12 cos (6 a)

x \to 0 + lim (\frac{8}{x ^{2} - x})

s l o p e in t erce pt (8.4) (4.1)

x \to - 1 - lim (f (x))

\frac{d}{d x} (\frac{a ^{2} + x ^{2}}{x})

\frac{\partial}{\partial x} (x^{2} y - x y^{3})