高中数学公式大全有哪些-pg电子官方网站

抛物线公式

y = ax^2 bx c 就是y等于ax的平方加上b

a > 0时开口向上

a < 0时开口向下

c = 0时抛物线经过原点

b = 0时抛物线对称轴为y轴

抛物线标准方程:y^2=2px

它表示抛物线的焦点在x的正半轴上,焦点坐标为(p/2,0)准线方程为x=-p/2

由于抛物线的焦点可在任意半轴,故共有标准方程y^2=2px y^2=-2px x^2=2py x^2=-2py

三角函数公式

sin(2kπ α)=sinα

cos(2kπ α)=cosα

tan(2kπ α)=tanα

cot(2kπ α)=cotα

sin(π α)=-sinα

cos(π α)=-cosα

tan(π α)=tanα

cot(π α)=cotα

sin(-α)=-sinα

cos(-α)=cosα

tan(-α)=-tanα

cot(-α)=-cotα

sin(π-α)=sinα

cos(π-α)=-cosα

tan(π-α)=-tanα

cot(π-α)=-cotα

sin(2π-α)=-sinα

cos(2π-α)=cosα

tan(2π-α)=-tanα

cot(2π-α)=-cotα

sin(π/2 α)=cosα

cos(π/2 α)=-sinα

tan(π/2 α)=-cotα

cot(π/2 α)=-tanα

sin(π/2-α)=cosα

cos(π/2-α)=sinα

tan(π/2-α)=cotα

cot(π/2-α)=tanα

sin(3π/2 α)=-cosα

cos(3π/2 α)=sinα

tan(3π/2 α)=-cotα

cot(3π/2 α)=-tanα

sin(3π/2-α)=-cosα

cos(3π/2-α)=-sinα

tan(3π/2-α)=cotα

cot(3π/2-α)=tanα

(以上k∈z)

sin(a b)=sinacosb cosasinb sin(a-b)=sinacosb-sinbcosa

cos(a b)=cosacosb-sinasinb cos(a-b)=cosacosb sinasinb

tan(a b)=(tana tanb)/(1-tanatanb) tan(a-b)=(tana-tanb)/(1 tanatanb)

ctg(a b)=(ctgactgb-1)/(ctgb ctga) ctg(a-b)=(ctgactgb 1)/(ctgb-ctga)

倍角公式

tan2a=2tana/(1-tan2a) ctg2a=(ctg2a-1)/2ctga

cos2a=cos2a-sin2a=2cos2a-1=1-2sin2a

半角公式

sin(a/2)=√((1-cosa)/2) sin(a/2)=-√((1-cosa)/2)

cos(a/2)=√((1 cosa)/2) cos(a/2)=-√((1 cosa)/2)

tan(a/2)=√((1-cosa)/((1 cosa)) tan(a/2)=-√((1-cosa)/((1 cosa))

ctg(a/2)=√((1 cosa)/((1-cosa)) ctg(a/2)=-√((1 cosa)/((1-cosa))

和差化积

2sinacosb=sin(a b) sin(a-b) 2cosasinb=sin(a b)-sin(a-b)

2cosacosb=cos(a b)-sin(a-b) -2sinasinb=cos(a b)-cos(a-b)

sina sinb=2sin((a b)/2)cos((a-b)/2 cosa cosb=2cos((a b)/2)sin((a-b)/2)

tana tanb=sin(a b)/cosacosb tana-tanb=sin(a-b)/cosacosb

ctga ctgbsin(a b)/sinasinb -ctga ctgbsin(a b)/sinasinb