初中數(shù)學知識點歸納總結(精華版)

零π7,23，。3314ab2313a2b35a3b2c是6（61axb0x為未知數(shù)，a）axb第1頁（311n把11把’11”（3實數(shù)第2頁a與b1—aaaaaa0aa（）aaa-（）a0aaaa33（—61a10n1a10n1ab0ab,ab0ab,ab0abbabaa1a;1a;1a;bbbbabab。ababb。22、xy（3第3頁xy0xy0x0,y0點點點x0,y0點在xy0x點在yx0，y點xyyP）點x與y點x與yxyxy點Px點Py點Py點到xx2y2x到y(tǒng)x18x第4頁（23xx,x,,x,12n1x)(x)x(x)]x[(x2s2222sn12n1x)(x)x(x)]x[(xs2222n12n11[(xxx)nx2]sx[(xx)]x2s2222222222nn1n1n1[(x'x'x')nx']s2221222nn'x'xaxa，?，'xa，那么，x均數(shù)接近的常數(shù)a，得到一組新數(shù)據(jù)，x1122nn1x's[(x'xx')]'2221222nnx'x'，xaxax'xa,x,,x,x12n1122nn',x',,x',x12n1x)(x)x(x)]xss[(x2222n12n第5頁（°b2ABC2∠∠180A2（32233第6頁P）yyyxyP）aa(,都是正整數(shù))a）a(,都是正整數(shù)amnmnmn(ab)ab(都是正整數(shù))(ab)(ab)ab2nnn2(ab)a2abb(ab)a2abb222222aa(,都是正整數(shù),a0)mnmn1a1(a0);a(a0,p為正整數(shù))0pap（abaca(bc)b(ab)(ab)a2abb(ab)a2abb(ab)a22222222a(cd)b(cd)(ab)(cd)(pq)apq(ap)(aq)a2AABBBBABBababacadbc(;cccbdbdacacacadadaa;;()nnnbdbdbdbcbcbba(aa第7頁a(a2a(a0)a2a）a(a0)aa(a0,b0)ab(ab））bb°12D為abcbc222°222AA°°°°°12223201123222αα1003313第8頁3α1033sinAcosA122sinAcosA（）abc°222ababbababsinA,cosA,tanA,cotA;sinB,cosB,tanB,cotBccbacca3n(n2)n(n3)。2（3S、S第9頁1(CDAB)DES2梯形ABCDSSSS①③；SS、函數(shù)（ykxbbkyx的ybb為0ykkyx的y隨xy隨x（(xa)bxaxab，是bb02xaba2abb(ab)2ax22bxb(xb)x。222bb4ac0(a0)x2b4ac0)axbxc222ab4ac。即2xbxxcx，。aa12128（（xb2ayaxbxc(a,b,是常數(shù)，a0)2第10頁ya(xh)2k(a,h,a0)yax2bxcaxbxc0和xx212bxca(xx)(xx)yaxaxbxc2212ya(xx)(xx)124b2xby當2a4a2a最值124b2bxxxy2a4a12最值xxxy隨xxx122ycycxxy隨x2222111ycycxxxx。22111222yaxbxc(a,b,是常數(shù)，a0)2yy0x0xbbbb2a2a，2a2a，4b24b24a4a第11頁bb2ay隨x2ay隨x的增大而減小；在對稱軸的右側，即當bb2ay隨x2ay隨xbb2ay2ay4b24b2yy4a4a最小值最大值aabab2accy，）當xxxAxyBxy）1122xy則xy221212圓））B第12頁（OPO點PO點PO點PO（3OOl（32（3R和））nrll180第13頁n1lRRSnR