高数常用公式
平方立方:
(1)a2?b2?(a?b)(a?b) (2)a2?2ab?b2?(a?b)2 (3)a2?2ab?b2?(a?b)2(4)a3?b3?(a?b)(a2?ab?b2) (5)a3?b3?(a?b)(a2?ab?b2) (6)a3?3a2b?3ab2?b3?(a?b)3 (7)a3?3a2b?3ab2?b3?(a?b)3 (8)a2?b2?c2?2ab?2bc?2ca?(a?b?c)2 (9)an?bn?(a?b)(an?1?an?2b??abn?2?bn?1),(n?2)
倒数关系:sinx·cscx=1 tanx·cotx=1 cosx·secx=1
商的关系:tanx=sinx/cosx cotx=cosx/sinx
平方关系:sin^2(x)+cos^2(x)=1 tan^2(x)+1=sec^2(x) cot^2(x)+1=csc^2(x)
倍角公式:
sin(2α)=2sinα·cosα
cos(2α)=cos^2(α)-sin^2(α)=2cos^2(α)-1=1-2sin^2(α) tan(2α)=2tanα/[1-tan^2(α)]
降幂公式:
sin^2(α/2)=(1-cosα)/2 cos^2(α/2)=(1+cosα)/2 tan^2(α/2)=(1-cosα)/(1+cosα) tan(α/2)=sinα/(1+cosα)=(1-cosα)/sinα
两角和差:
sin(α±β)=sinα·cosβ±cosα·sinβ cos(α+β)=cosα·cosβ-sinα·sinβ cos(α-β)=cosα·cosβ+sinα·sinβ tan(α+β)=(tanα+tanβ)/(1-tanα·tanβ) tan(α-β)=(tanα-tanβ)/(1+tanα·tanβ)
积化和差:
sinα·cosβ=(1/2)[sin(α+β)+sin(α-β)] cosα·sinβ=(1/2)[sin(α+β)-sin(α-β)] cosα·cosβ=(1/2)[cos(α+β)+cos(α-β)] sinα·sinβ=-(1/2)[cos(α+β)-cos(α-β)]
和差化积:
sinα+sinβ=2sin[(α+β)/2]cos[(α-β)/2] sinα-sinβ=2cos[(α+β)/2]sin[(α-β)/2] cosα+cosβ=2cos[(α+β)/2]cos[(α-β)/2] cosα-cosβ=-2sin[(α+β)/2]sin[(α-β)/2]
特殊角的三角函数值: ? f(?) 0 ?6 ?4 ?3 ?2 π 3?2 2π (0?) 0 1 0 不存在 (30?) (45?) (60?) 3/2 (90?) 1 0 不存在 0 (180?) 0 -1 0 不存在 (270?) -1 0 不存在 0 (360?) 0 1 0 不存在 sin? cos? tan? cot? 1/2 3/2 1/3 3 2/2 2/2 1 1 1/2 3 1/3
等价代换:
nx (4) arcta~nx (1) sinx~x (2) tanx~x (3) arcsi~1ax(5) 1?cos~xx2 (6) ln(1?x)~x (7) e?1~x (8) (1?x)?1~ax
2
基本求导公式:
(1) (C)??0 ,C是常数 (2) (x?)???x??1 (3) (ax)??axlna (4) (logax)??1 xlna(5) (sinx)??cosx (6) (cosx)???sinx (7) (tanx)??112?(cotx)????csc2x ?secx (8) 22cosxsinxc)??(sexc)tanx (10) (cscx)???(cscx)cotx (9) (sex(11) (arcsinx)??11?x2 (12) (arccosx)???11?x2
(13) (arctanx)??11?(arccotx)?? (14)
1?x21?x2()?? (16)
1x1 x2??(x)(15)
12x
基本积分公式:
(1) ?0dx?C (2)
?kdx?kx?C?k为常数?
?
x??1?C????1? (3) ?xdx???1(4)
1?xdx?ln|x|?C
xax?C (5) ?adx?lna(6) ?exdx?ex?C (7) ?cosxdx?sinx?C (8) ?sinxdx??cosx?C
dx2?sec?cos2x?xdx?tanx?C dx(10) ?2??csc2xdx??cotx?C
sinx(9)
(11) ?secxtanxdx?secx?C (12) ?cscxcotxdx??cscx?C (13) (14) (15)
dxdx 或(?arctanx?C?1?x2?1?x2??arccotx?C)
?dx1?x2?arcsinx?C 或(?dx1?x2??arccosx?C)
?tanxdx??ln|cosx|?C,
(16) ?cotxdx?ln|sinx|?C, (17) ?secxdx?ln|secx?tanx|?C, (18) ?cscxdx?ln|cscx?cotx|?C,