对数与对数运算三VIP免费

对数的运算法则当a＞0,且a≠1,且M＞0,N＞0时,有：)(log)1(NMaNMaaloglogNMalog)2(NMaaloglognaMlog)3(Mnalog换底公式及推论yxlogxyaaloglognabmlogbmnalogabbaloglog1dcbcbalogloglogdalog5log13333log42225log12)2(15log3)2(33165325165295log3lg33log45log1223)21(1023.133lg)10(练习:2.设a=lg2,b=lg3,试用a,b表示下列各式:(1)lg6(2)lg12(3)lg325(5)log188(4)log27练习:ab2ab52aba21aba25log264log6)1.(35148.1lg10lg3lg2lg)2()3log3)(log2log2(log.58493.)21(2,10054.4的值求设baba25lg50lg2lg2lg.62.解下列方程例)3(log)1(log)13(log)1(333xxx1)123(log)2(2)12(2xxx