中學數(shù)學公式歸納

1、1高中數(shù)學常用公式及常用結(jié)論1.德摩根公式()()UUUUUUCABCACBCABCACB??????.2.UUABAABBABCBCA?????????UACB????UCABR???3.()()cardABcardAcardBcardAB?????()()cardABCcardAcardBcardCcardAB???????()()()()cardABcardBCcardCAcardABC?????????.4、集合12naaa?的

2、子集個數(shù)共有2n個；真子集有2n–1個；非空子集有2n–1個；非空的真子集有2n–2個.5.二次函數(shù)的解析式的三種形式①一般式2()(0)fxaxbxca????②頂點式2()()(0)fxaxhka????③零點式12()()()(0)fxaxxxxa????.6.函數(shù)()yfx?的圖象的對稱性:①函數(shù)()yfx?的圖象關(guān)于直線xa?對稱()()faxfax????(2)()faxfx???.②函數(shù)()yfx?的圖象關(guān)于直線2abx?

3、?對稱()()famxfbmx????()()fabmxfmx????.7.兩個函數(shù)圖象的對稱性:①函數(shù)()yfx?與函數(shù)()yfx??的圖象關(guān)于直線0x?(即y軸)對稱.②函數(shù)()yfmxa??與函數(shù)()yfbmx??的圖象關(guān)于直線2abxm??對稱.③函數(shù))(xfy?和)(1xfy??的圖象關(guān)于直線y=x對稱.8奇偶函數(shù)的圖象特征：奇函數(shù)的圖象關(guān)于原點對稱，偶函數(shù)的圖象關(guān)于y軸對稱反過來，如果一個函數(shù)的圖象關(guān)于原點對稱，那么這個函數(shù)

4、是奇函數(shù)；如果一個函數(shù)的圖象關(guān)于y軸對稱，那么這個函數(shù)是偶函數(shù)9.分數(shù)指數(shù)冪nmnmaa1??（0amnN???，且1n?）.1mnmnaa??（0amnN???，且1n?）.10、根式的性質(zhì)（1）()nnaa?.（2）當n為奇數(shù)時，nnaa?；當n為偶數(shù)時，0||0nnaaaaaa????????3qpmnaaaa???qpmnaaaa?前n項和公式????dnnnaaanSnn21211???????.11111111???????

5、?????qqqaaqqaqnaSnnn，－一個性質(zhì)mmmSSS32成等差數(shù)列mmmSSS32成等比數(shù)列18、直線的五種方程：（1）點斜式11()yykxx???(直線l過點111()Pxy，且斜率為k)（2）斜截式y(tǒng)kxb??(b為直線l在y軸上的截距).（3）兩點式112121yyxxyyxx?????(12yy?)(111()Pxy、222()Pxy(12xx?)).(4)截距式1xyab??(ab、分別為直線的橫、縱截距，0ab

6、?、)（5）一般式0AxByC???(其中A、B不同時為0).19、兩條直線的平行和垂直(1)若111:lykxb??，222:lykxb??①121212||llkkbb???②12121llkk????.(2)若1111:0lAxByC???2222:0lAxByC???且A1、A2、B1、B2都不為零①11112222||ABCllABC???；②1212120llAABB????；(3)平行直線系方程：直線ykxb??中當斜率k