d/(dt)(2cos(3t))

解答

\frac{d}{d t} (2 cos (3 t))

- 6 sin (3 t)

求解步骤

\frac{d}{d t} (2 cos (3 t))

将常数提出:

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

= 2 \frac{d}{d t} (cos (3 t))

使用连锁律:

- sin (3 t) \frac{d}{d t} (3 t)

= - sin (3 t) \frac{d}{d t} (3 t)

\frac{d}{d t} (3 t) = 3

= 2 (- sin (3 t) \cdot 3)

化简

= - 6 sin (3 t)

\int_{0}^{\frac{9}{10}} \frac{1}{( 100 x ^{2} + 1 ) ^{\frac{3}{2}}} d x

12 x^{3} - 3 y^{2} x^{4} + 1 \cdot y^{^{'}} = 0

\int \frac{1}{( x ^{2} - 49 ) ^{2}} d x

d er i v a t i v e f (x) = 2 x + 2

x \to 4 lim (\frac{7}{x - 4})