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积分与求导常用公式总结

#数学#高等数学#积分#导数

一、求导公式

1. 基本初等函数的导数

  • 常数:(C)=0(C)' = 0
  • 幂函数:(xμ)=μxμ1(x^\mu)' = \mu x^{\mu-1}μ\mu 为实数)
  • 指数函数:(ex)=ex(e^x)' = e^x(ax)=axlna(a^x)' = a^x \ln a
  • 对数函数:(lnx)=1x(\ln x)' = \frac{1}{x}(logax)=1xlna(\log_a x)' = \frac{1}{x \ln a}
  • 三角函数:
    • (sinx)=cosx(\sin x)' = \cos x
    • (cosx)=sinx(\cos x)' = -\sin x
    • (tanx)=sec2x(\tan x)' = \sec^2 x
    • (cotx)=csc2x(\cot x)' = -\csc^2 x
    • (secx)=secxtanx(\sec x)' = \sec x \tan x
    • (cscx)=cscxcotx(\csc x)' = -\csc x \cot x
  • 反三角函数:
    • (arcsinx)=11x2(\arcsin x)' = \frac{1}{\sqrt{1-x^2}}
    • (arccosx)=11x2(\arccos x)' = -\frac{1}{\sqrt{1-x^2}}
    • (arctanx)=11+x2(\arctan x)' = \frac{1}{1+x^2}
    • (arccotx)=11+x2(\operatorname{arccot} x)' = -\frac{1}{1+x^2}

2. 求导法则

  • 线性法则(u±v)=u±v(u \pm v)' = u' \pm v'(cu)=cu(cu)' = c u'
  • 乘积法则(uv)=uv+uv(uv)' = u'v + uv'
  • 商法则(uv)=uvuvv2\left(\frac{u}{v}\right)' = \frac{u'v - uv'}{v^2}v0v \neq 0
  • 链式法则[f(g(x))]=f(g(x))g(x)[f(g(x))]' = f'(g(x)) \cdot g'(x)
  • 反函数求导:若 y=f(x)y = f(x) 可导且 f(x)0f'(x) \neq 0,则反函数 x=φ(y)x = \varphi(y) 的导数为 φ(y)=1f(x)\varphi'(y) = \frac{1}{f'(x)}dxdy=1dy/dx\frac{dx}{dy} = \frac{1}{dy/dx}
  • 隐函数求导:由 F(x,y)=0F(x,y)=0 确定 y=y(x)y=y(x),则 dydx=FxFy\frac{dy}{dx} = -\frac{F_x}{F_y}Fy0F_y \neq 0
  • 参数方程求导{x=x(t)y=y(t)\begin{cases} x = x(t) \\ y = y(t) \end{cases},则 dydx=y(t)x(t)\frac{dy}{dx} = \frac{y'(t)}{x'(t)},二阶导 d2ydx2=x(t)y(t)y(t)x(t)[x(t)]3\frac{d^2y}{dx^2} = \frac{x'(t)y''(t) - y'(t)x''(t)}{[x'(t)]^3}

二、积分公式

1. 不定积分基本公式(与导数对应)

  • kdx=kx+C\int k \, dx = kx + C
  • xμdx=xμ+1μ+1+C\int x^\mu \, dx = \frac{x^{\mu+1}}{\mu+1} + Cμ1\mu \neq -1
  • 1xdx=lnx+C\int \frac{1}{x} \, dx = \ln|x| + C
  • exdx=ex+C\int e^x \, dx = e^x + C
  • axdx=axlna+C\int a^x \, dx = \frac{a^x}{\ln a} + C
  • sinxdx=cosx+C\int \sin x \, dx = -\cos x + C
  • cosxdx=sinx+C\int \cos x \, dx = \sin x + C
  • sec2xdx=tanx+C\int \sec^2 x \, dx = \tan x + C
  • csc2xdx=cotx+C\int \csc^2 x \, dx = -\cot x + C
  • secxtanxdx=secx+C\int \sec x \tan x \, dx = \sec x + C
  • cscxcotxdx=cscx+C\int \csc x \cot x \, dx = -\csc x + C
  • tanxdx=lncosx+C\int \tan x \, dx = -\ln|\cos x| + C
  • cotxdx=lnsinx+C\int \cot x \, dx = \ln|\sin x| + C
  • secxdx=lnsecx+tanx+C\int \sec x \, dx = \ln|\sec x + \tan x| + C
  • cscxdx=lncscxcotx+C\int \csc x \, dx = \ln|\csc x - \cot x| + C
  • 11x2dx=arcsinx+C\int \frac{1}{\sqrt{1-x^2}} \, dx = \arcsin x + C(或 arccosx+C-\arccos x + C
  • 11+x2dx=arctanx+C\int \frac{1}{1+x^2} \, dx = \arctan x + C(或 arccotx+C-\operatorname{arccot} x + C
  • 1a2x2dx=arcsinxa+C\int \frac{1}{\sqrt{a^2-x^2}} \, dx = \arcsin\frac{x}{a} + Ca>0a>0
  • 1a2+x2dx=1aarctanxa+C\int \frac{1}{a^2+x^2} \, dx = \frac{1}{a} \arctan\frac{x}{a} + C
  • 1x2a2dx=12alnxax+a+C\int \frac{1}{x^2-a^2} \, dx = \frac{1}{2a} \ln\left|\frac{x-a}{x+a}\right| + C
  • 1x2±a2dx=lnx+x2±a2+C\int \frac{1}{\sqrt{x^2 \pm a^2}} \, dx = \ln\left|x + \sqrt{x^2 \pm a^2}\right| + C

2. 积分运算法则

  • 线性性质[f(x)±g(x)]dx=f(x)dx±g(x)dx\int [f(x) \pm g(x)] \, dx = \int f(x) \, dx \pm \int g(x) \, dxkf(x)dx=kf(x)dx\int k f(x) \, dx = k \int f(x) \, dx
  • 分部积分法udv=uvvdu\int u \, dv = uv - \int v \, du(选 uu 遵循“反对幂三指”顺序)
  • 换元积分法
    • 第一类换元(凑微分)f(φ(x))φ(x)dx=f(u)du\int f(\varphi(x)) \varphi'(x) \, dx = \int f(u) \, du,令 u=φ(x)u = \varphi(x)
    • 第二类换元f(x)dx\int f(x) \, dx,令 x=ψ(t)x = \psi(t),则 dx=ψ(t)dtdx = \psi'(t) \, dt,转化为 f(ψ(t))ψ(t)dt\int f(\psi(t)) \psi'(t) \, dt,常用于去根号(三角代换、倒代换等)

3. 定积分常用公式与性质

  • 牛顿-莱布尼茨公式abf(x)dx=F(b)F(a)\int_a^b f(x) \, dx = F(b) - F(a),其中 F(x)=f(x)F'(x) = f(x)
  • 线性性质:同不定积分
  • 换元法abf(x)dx=αβf(φ(t))φ(t)dt\int_a^b f(x) \, dx = \int_\alpha^\beta f(\varphi(t)) \varphi'(t) \, dt,需换限
  • 分部积分法abudv=[uv]ababvdu\int_a^b u \, dv = [uv]_a^b - \int_a^b v \, du
  • 奇偶对称性
    • f(x)f(x) 为偶函数,则 aaf(x)dx=20af(x)dx\int_{-a}^a f(x) \, dx = 2 \int_0^a f(x) \, dx
    • f(x)f(x) 为奇函数,则 aaf(x)dx=0\int_{-a}^a f(x) \, dx = 0
  • 周期性:若 f(x)f(x)TT 为周期,则 aa+Tf(x)dx=0Tf(x)dx\int_a^{a+T} f(x) \, dx = \int_0^T f(x) \, dx
  • 华里士公式(点火公式)
    • 0π/2sinnxdx=0π/2cosnxdx={(n1)!!n!!π2,n为正偶数(n1)!!n!!,n为正奇数\int_0^{\pi/2} \sin^n x \, dx = \int_0^{\pi/2} \cos^n x \, dx = \begin{cases} \frac{(n-1)!!}{n!!} \cdot \frac{\pi}{2}, & n \text{为正偶数} \\ \frac{(n-1)!!}{n!!}, & n \text{为正奇数} \end{cases}
  • 区间再现公式abf(x)dx=abf(a+bx)dx\int_a^b f(x) \, dx = \int_a^b f(a+b-x) \, dx
  • 欧拉积分0π/2lnsinxdx=π2ln2\int_0^{\pi/2} \ln\sin x \, dx = -\frac{\pi}{2} \ln 2

三、多元函数微积分常用公式(补充)

  • 偏导数zx\frac{\partial z}{\partial x}zy\frac{\partial z}{\partial y}z=f(x,y)z = f(x,y)
  • 全微分dz=zxdx+zydydz = \frac{\partial z}{\partial x} \, dx + \frac{\partial z}{\partial y} \, dy
  • 梯度gradf=(fx,fy,fz)\operatorname{grad} f = \left( \frac{\partial f}{\partial x}, \frac{\partial f}{\partial y}, \frac{\partial f}{\partial z} \right)
  • 多元复合函数求导(链式法则):如 z=f(u,v)z = f(u,v)u=φ(x,y)u = \varphi(x,y)v=ψ(x,y)v = \psi(x,y),则 zx=fuux+fvvx\frac{\partial z}{\partial x} = \frac{\partial f}{\partial u} \frac{\partial u}{\partial x} + \frac{\partial f}{\partial v} \frac{\partial v}{\partial x}
  • 隐函数求导:由 F(x,y,z)=0F(x,y,z)=0 确定 z=z(x,y)z = z(x,y),则 zx=FxFz\frac{\partial z}{\partial x} = -\frac{F_x}{F_z}zy=FyFz\frac{\partial z}{\partial y} = -\frac{F_y}{F_z}
  • 重积分换元Df(x,y)dxdy=Df(x(u,v),y(u,v))Jdudv\iint_D f(x,y) \, dxdy = \iint_{D'} f(x(u,v), y(u,v)) \, |J| \, du dv,其中 J=(x,y)(u,v)J = \frac{\partial(x,y)}{\partial(u,v)}
  • 曲线积分、曲面积分等相关公式(如格林公式、高斯公式、斯托克斯公式)在此略去,可根据需要另行总结。

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