derivative of (cos(2x)/2)

解答

\frac{d}{d x} (\frac{cos ( 2 x )}{2})

- sin (2 x)

求解步骤

\frac{d}{d x} (\frac{cos ( 2 x )}{2})

将常数提出:

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

= \frac{1}{2} \frac{d}{d x} (cos (2 x))

使用连锁律:

- sin (2 x) \frac{d}{d x} (2 x)

= - sin (2 x) \frac{d}{d x} (2 x)

\frac{d}{d x} (2 x) = 2

= \frac{1}{2} (- sin (2 x) \cdot 2)

化简

\frac{1}{2} (- sin (2 x) \cdot 2) : - sin (2 x)

= - sin (2 x)

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

n = 1 \sum \infty \frac{1}{9 ^{n}}

\frac{d}{d x} (\frac{x - 1}{x + 1})

x \to 4 lim (\frac{∣ 3 - x ∣}{3 - x})

\int_{0}^{\frac{π}{4}} cos^{2} (x) d x