常用数学公式
常用函数导数
多项式函数:
- ( (ax^n)' = nax^{(n-1)} )
指数函数和对数函数:
- ( (e^x)' = e^x )
- ( (a^x)' = \ln(a) \cdot a^x )
- ( (\ln(x))' = \frac{1}{x} )
三角函数:
- ( (\sin(x))' = \cos(x) )
- ( (\cos(x))' = -\sin(x) )
- ( (\tan(x))' = \sec^2(x) )
反三角函数:
- ( (\arcsin(x))' = \frac{1}{\sqrt{1-x^2}} )
- ( (\arccos(x))' = -\frac{1}{\sqrt{1-x^2}} )
- ( (\arctan(x))' = \frac{1}{1+x^2} )
双曲函数:
- ( (\sinh(x))' = \cosh(x) )
- ( (\cosh(x))' = \sinh(x) )
- ( (\tanh(x))' = \text{sech}^2(x) )
反双曲函数:
- ( (\text{arsinh}(x))' = \frac{1}{\sqrt{x^2 + 1}} )
- ( (\text{arcosh}(x))' = \frac{1}{\sqrt{x^2 - 1}} )
- ( (\text{artanh}(x))' = \frac{1}{1-x^2} )
对数函数:
- ( (\log_a(x))' = \frac{1}{x \cdot \ln(a)} )
幂函数:
- ( (x^a)' = ax^{(a-1)} )
注意,这些公式是在函数的定义域内有效,且有时需要其他条件(比如,函数必须是可微的)。
函数的和、差、积、商的求导法则
和/差的求导法则:
- 如果 ( f ) 和 ( g ) 是可导函数,则它们的和/差的导数为: [ (f + g)' = f' + g' ] [ (f - g)' = f' - g' ]
积的求导法则(乘法法则):
- 如果 ( f ) 和 ( g ) 是可导函数,则它们的积的导数为: [ (fg)' = f'g + fg' ]
商的求导法则:
- 如果 ( f ) 和 ( g ) 是可导函数且 ( g \neq 0 ),则它们的商的导数为: [ \left(\frac{f}{g}\right)' = \frac{f'g - fg'}{g^2} ]
基本积分表
- $ \int kdx = kx + C $
- $ \int x^{\alpha} dx = \frac{x^{\alpha+1}}{\alpha+1} + C \quad (\alpha \neq 1) $
- $ \int \frac{dx}{x} = \ln |x| + C $
- $ \int \frac{dx}{1 + x^2} = \arctan x + C $
- $ \int \frac{dx}{\sqrt{1 - x^2}} = \arcsin x + C $
- $ \int \cos dx = \sin x + C $
- $ \int \sin dx = -\cos x + C $
- $ \int \frac{dx}{\cos^2 x} = \int \sec^2 x dx = \tan x + C $
- $ \int \frac{dx}{\sin^2 x} = \int \csc^2 x dx = -\cot x + C $
- $ \int \sec x \tan x dx = \sec x + C $
- $ \int \csc x \cot x dx = -\csc x + C $
- $ \int e^x dx = e^x + C $
- $ \int a^x dx = \frac{a^x}{\ln a} + C $
- $ \int \sinh x dx = \cosh x + C $
- $ \int \cosh x dx = \sinh x + C $
- $ \int \tan x dx = -\ln |\cos x| + C $
- $ \int \cot x dx = \ln |\sin x| + C $
- $ \int \sec x dx = \ln |\sec x + \tan x| + C $
- $ \int \csc x dx = -\ln |\csc x + \cot x| + C $
- $ \int \frac{dx}{a^2 + x^2} = \frac{1}{a} \arctan \frac{x}{a} + C $
- $ \int \frac{dx}{a^2 - x^2} = \frac{1}{2a} \ln \frac{a + x}{a - x} + C $
- $ \int \frac{dx}{\sqrt{a^2 - x^2}} = \arcsin \frac{x}{a} + C $
- $ \int \frac{dx}{\sqrt{x^2 + a^2}} = \ln \left( x + \sqrt{x^2 + a^2} \right) + C $
- $ \int \frac{dx}{\sqrt{x^2 - a^2}} = \ln \left( x + \sqrt{x^2 - a^2} \right) + C $