🧠 基本求导公式 使用LaTeX排版
1. 幂函数
\frac{d}{dx} (x^n) = n x^{n-1}
推导:
\frac{d}{dx}x^n=\lim_{h\to 0}\frac{(x+h)^n-x^n}{h} \\[10pt]
(x+h)^n = x^n + n x^{n-1}h + \frac{n(n-1)}{2}x^{n-2}h^2+\cdots
\frac{(x+h)^n-x^n}{h}=n x^{n-1}+\frac{n(n-1)}{2}x^{n-2}h+\cdots
\frac{d}{dx}x^n = n x^{n-1}
2. 指数函数
\frac{d}{dx} e^x = e^x
推导:
\frac{d}{dx}e^x
=\lim_{h\to 0} \frac{e^{x+h} - e^x}{h}
= e^x\lim_{h\to 0} \frac{e^h - 1}{h} \\[6pt]
而数学中有\quad \lim_{h\to 0} \frac{e^h - 1}{h}=1 \quad
于是\frac{d}{dx}e^x= e^x
3. 对数函数
\frac{d}{dx} \ln x = \frac{1}{x}
推导:
y=\ln x \Rightarrow x=e^y \\[6pt]
1=\frac{dy}{dx} e^y = \frac{dy}{dx} x \\[6pt]
\frac{dy}{dx}=\frac{1}{x}
4. 三角函数
(1) 正弦
\frac{d}{dx}\sin x = \cos x
推导:
\frac{\sin(x+h)-\sin x}{h}
= \sin x\frac{\cos h-1}{h}+\cos x\frac{\sin h}{h} \\[6pt]
\lim_{h\to 0}\frac{\sin h}{h}=1,\quad
\lim_{h\to 0}\frac{\cos h -1}{h}=0 \\[6pt]
\frac{d}{dx}\sin x = \cos x
(2) 余弦
\frac{d}{dx}\cos x = -\sin x
推导:
\frac{\cos(x+h)-\cos x}{h}
= -\sin x\frac{\sin h}{h} + \cos x\frac{\cos h -1}{h}
\frac{d}{dx}\cos x = -\sin x
5. 常数函数
\frac{d}{dx} C = 0
6.乘积法则
\frac{d}{dx}[u(x)v(x)]
= u'(x)v(x) + u(x)v'(x)
推导:
\frac{d}{dx}[uv] \\[6pt]
= \lim_{h\to 0} \frac{u(x+h)v(x+h)-u(x)v(x)}{h} \\[6pt]
= \lim_{h\to 0} \frac{u(x+h)v(x+h)-u(x)v(x+h)+u(x)v(x+h)-u(x)v(x)}{h} \\[6pt]
= \lim_{h\to 0} \left[ v(x+h)\frac{u(x+h)-u(x)}{h} \\[6pt]
+ u(x)\frac{v(x+h)-v(x)}{h} \right] \\[6pt]
= u'(x)v(x) + u(x)v'(x)
7.商数法则
\frac{d}{dx}\left(\frac{u(x)}{v(x)}\right)
= \frac{u'(x)v(x)-u(x)v'(x)}{[v(x)]^2}
推导:
\frac{d}{dx}\left(\frac{u}{v}\right)
= \frac{d}{dx}[u \cdot v^{-1}]
= u'(x)v^{-1} + u(x)(-1)v^{-2}v'
= \frac{u'v - uv'}{v^2}
8.链式法则
\frac{d}{dx} f(g(x))
= f'(g(x)) \cdot g'(x)
推导(最经典的 ε-h 极限推导):
\frac{d}{dx}f(g(x)) \\[6pt]
= \lim_{h\to 0} \frac{f(g(x+h)) - f(g(x))}{h} \\[6pt]
设 \Delta g = g(x+h) - g(x) \\[6pt]
= \lim_{h\to 0} \frac{f(g(x)+\Delta g)-f(g(x))}{\Delta g} \cdot \frac{\Delta g}{h} \\[6pt]
= f'(g(x)) \cdot g'(x)
🌟最基础函数求导表
\frac{d}{dx} (x^n) = n x^{n-1}\quad
\frac{d}{dx} e^x = e^x\quad
\frac{d}{dx} \ln x = \frac{1}{x}\quad
\frac{d}{dx} \sin x = \cos x\quad
\frac{d}{dx} \cos x = -\sin x\quad
\frac{d}{dx} \tan x = \sec^2 x \\[6pt]
\frac{d}{dx} \cot x = -\csc^2 x\quad
\frac{d}{dx} \sec x = \sec x \tan x\quad
\frac{d}{dx} \csc x = -\csc x \cot x\quad
\frac{d}{dx} C = 0
🌌 常见复合示例
\frac{d}{dx} \ln(ax+b) = \frac{a}{ax+b} \quad
\frac{d}{dx} e^{kx} = k e^{kx} \quad
\frac{d}{dx} \sin(kx) = k \cos(kx) \quad
\frac{d}{dx} \cos(kx) = -k \sin(kx) \\[6pt]
\frac{d}{dx} (a x^n + b x + c) = a n x^{n-1} + b
🌙《高数(一)》常用与必背的求导公式全集
一、幂函数、指数、对数
\frac{d}{dx}(x^n) = n x^{n-1} \quad
\frac{d}{dx}(a^x) = a^x \ln a \quad
\frac{d}{dx}(e^x) = e^x \quad
\frac{d}{dx}(\ln x) = \frac{1}{x} \quad
\frac{d}{dx}(\log_a x) = \frac{1}{x \ln a}
二、三角函数
\frac{d}{dx}(\sin x) = \cos x \quad
\frac{d}{dx}(\cos x) = -\sin x \quad
\frac{d}{dx}(\tan x) = \sec^2 x \quad
\frac{d}{dx}(\cot x) = -\csc^2 x \quad
\frac{d}{dx}(\sec x) = \sec x \tan x \quad
\frac{d}{dx}(\csc x) = -\csc x \cot x \quad
三、反三角函数
\frac{d}{dx}(\arcsin x) = \frac{1}{\sqrt{1 - x^2}} \quad
\frac{d}{dx}(\arccos x) = -\frac{1}{\sqrt{1 - x^2}} \quad
\frac{d}{dx}(\arctan x) = \frac{1}{1 + x^2} \quad
\frac{d}{dx}(arccot x) = -\frac{1}{1 + x^2}
四、双曲函数(高数常考)
\frac{d}{dx}(\sinh x) = \cosh x \quad
\frac{d}{dx}(\cosh x) = \sinh x \quad
\frac{d}{dx}(\tanh x) = \text{sech}^2 x \quad
\frac{d}{dx}(\coth x) = -\text{csch}^2 x
五、双曲反函数
\frac{d}{dx}(\operatorname{arcsinh} x) = \frac{1}{\sqrt{x^2 + 1}} \quad
\frac{d}{dx}(\operatorname{arccosh} x) = \frac{1}{\sqrt{x-1}\sqrt{x+1}} \quad
\frac{d}{dx}(\operatorname{arctanh} x) = \frac{1}{1 - x^2}
六、常见复合与结构性函数
\frac{d}{dx}(\ln(ax+b)) = \frac{a}{ax+b} \quad
\frac{d}{dx}(e^{kx}) = k e^{kx} \quad
\frac{d}{dx}(\sin(kx)) = k\cos(kx) \quad
\frac{d}{dx}(\cos(kx)) = -k\sin(kx) \\[6pt]
\frac{d}{dx}(\tan(kx)) = k\sec^2(kx) \quad
\frac{d}{dx}(x^n e^{kx}) = x^n k e^{kx} + n x^{n-1} e^{kx} \quad
\frac{d}{dx}(a x^n + b x + c) = a n x^{n-1} + b
七、乘积法则、商数法则、链式法则
\frac{d}{dx}[u(x)v(x)] = u'(x)v(x) + u(x)v'(x) \quad
\frac{d}{dx}\left(\frac{u(x)}{v(x)}\right) =
\frac{u'(x)v(x) - u(x)v'(x)}{[v(x)]^{2}} \quad
\frac{d}{dx}(f(g(x))) = f'(g(x)) g'(x) \\[6pt]
八、常数函数与线性函数
\frac{d}{dx}(C) = 0 \quad
\frac{d}{dx}(ax + b) = a