常用转换公式
1 + t a n 2 x = s e c 2 x 1+tan^2x=sec^2x 1+tan2x=sec2x
导数
( l o g a x ) ′ = 1 x l n a (log_ax)'=\frac{1}{xlna} (logax)′=xlna1
( a x ) ′ = a x l n a (a^x)'=a^xlna (ax)′=axlna
由反函数公式推导出的导数: x = f ( y ) 的 反 函 数 y = f − 1 ( x ) x=f(y)的反函数y=f^{-1}(x) x=f(y)的反函数y=f−1(x)的导数 [ f − 1 ( x ) ] ′ = 1 f ′ ( y ) [f^{-1}(x)]'=\frac{1}{f'(y)} [f−1(x)]′=f′(y)1
( a r c s i n x ) ′ = 1 1 − x 2 (arcsinx)'=\frac{1}{\sqrt{1-x^2}} (arcsinx)′=1−x21
( a r c c o s x ) ′ = − 1 1 − x 2 (arccosx)'=-\frac{1}{\sqrt{1-x^2}} (arccosx)′=−1−x21
( a r c t a n x ) ′ = 1 1 + x 2 (arctanx)'=\frac{1}{1+x^2} (arctanx)′=1+x21
( a r c c o t x ) ′ = − 1 1 + x 2 (arccotx)'=-\frac{1}{1+x^2} (arccotx)′=−1+x21
三角函数:
( t a n x ) ′ = s e c 2 x (tanx)'=sec^2x (tanx)′=sec2x
( c o t x ) ′ = − c s c 2 x (cotx)'=-csc^2x (cotx)′=−csc2x
( s e c x ) ′ = s e c x t a n x (secx)'=secxtanx (secx)′=secxtanx
( c s c x ) ′ = − c s c x c o t x (cscx)'=-cscxcotx (cscx)′=−cscxcotx
积分
换元积分法转换公式:
∫ f ( θ ( x ) ) θ ′ ( x ) d x = ∫ f ( u ) d u ∣ u = θ ( x ) \int f(\theta(x))\theta'(x)dx=\int f(u)du|_{u=\theta(x)} ∫f(θ(x))θ′(x)dx=∫f(u)du∣u=θ(x)
定积分求导数
[ ∫ φ 1 ( x ) φ 2 ( x ) f ( t ) d t ] ′ = f [ φ 2 ( x ) ] φ 2 ′ ( x ) − f [ φ 1 ( x ) ] φ 1 ′ ( x ) \left[\int _{\varphi_1(x) }^{\varphi_2(x)} f(t) dt \right]^{'} = f[\varphi_2(x)] \varphi_2^{'}(x) - f[\varphi_1(x)] \varphi_1^{'}(x) [∫φ1(x)φ2(x)f(t)dt]′=f[φ2(x)]φ2′(x)−f[φ1(x)]φ1′(x)
特别地:
[ ∫ a x f ( t ) d t ] ′ = f ( x ) \left[\int _a^{x}f(t)dt \right]^{'} =f(x) \\ [∫axf(t)dt]′=f(x)
万能公式
∫ s e c 2 x d x = t a n x \int sec^2x dx =tanx ∫sec2xdx=tanx
1 + t a n 2 x = s e c 2 x 1+tan^2 x=sec^2x 1+tan2x=sec2x
∫ s e c x t a n x d x = s e c x \int secx tanx dx=secx ∫secxtanxdx=secx
∫ s e c x d x = l n ∣ s e c x + t a n x ∣ \int secx dx=ln|sec x+tanx| ∫secxdx=ln∣secx+tanx∣
速记
- ∫ t a n x d x = − l n ∣ c o s x ∣ \int tanxdx=-ln|cosx| ∫tanxdx=−ln∣cosx∣
- ∫ c o t x d x = l n ∣ s i n x ∣ \int cotxdx=ln|sinx| ∫cotxdx=ln∣sinx∣
- ∫ s e c x d x = l n ∣ s e c x + t a n x ∣ \int secx dx=ln|secx+tanx| ∫secxdx=ln∣secx+tanx∣
- ∫ c s c x d x = l n ∣ c s c x − c o t x ∣ \int cscxdx=ln|cscx-cotx| ∫cscxdx=ln∣cscx−cotx∣
微分方程求原函数
d y d x + P ( x ) y = Q ( x ) \frac{dy}{dx} +P(x) y=Q(x) dxdy+P(x)y=Q(x) 其通解为:
y = e − u ( ∫ Q ( x ) u + C ) y=e^{-u} (\int Q(x) u +C) y=e−u(∫Q(x)u+C)
其中 u = e ∫ P ( x ) d x u=e^{\int P(x)dx} u=e∫P(x)dx