高中数学 321对数及其运算(二)课件 新人教B版必修1 课件VIP免费

指数的运算性质有哪些？()mnmnmmnnmnmnaaaaaaaa你能从指数与对数的关系以及指数运算性质得出相应的对数运算性质吗？积、商、幂的对数运算法则如果a>0，a1，M>0,N>0,则有：logloglog()logloglog()loglog()aaaaaaaaMNMNMMNNMMR()12()3,,,logloglogpqpqpqpnpqaaaMaNaMNaaaMNaaapq所以log,log,aaMpNq则logloglogaaaMNMN(1)化简下列各式2231.lg2lg512.loglog633.log27819logloglogloglogppqaaaaaqMaapqMNNalogloglogaaaMMNN32211(1).log(2).lg25lg27451(3).log6log3(4).lg12.5lglg82化简下列各式(),logloglogpppaaaMaaMapM（3）化简下列各式635321(1)log(2)log(3)log(981)125axxloglogaaMM推广：111logloglog1logloglognnaaaaaaMMMnMMM例题与练习例1用，，表示下列各式：xalogyalogzalog2353(1)log;(2)log();(3)log;(4)logaaaaxyxyxxyzyzz例2计算)24(log572(2)5100lg(3)lg4lg25（1）2(4)(lg2)lg20lg51.lg2,lg3,,lg45abab已知用表示的值。32.32,35,,log30abab已知用表示的值。跟进练习：求下列各式的值：（1）2(lg5)lg2lg5lg2（2）lg2lg50-lg5lg20+lg25积、商、幂的对数运算法则如果a>0，a1，M>0,N>0,则有：logloglog()logloglog()loglog()aaaaaaaMNMNMMNNMMR()12()3推广：111logloglog1logloglognnaaaaaaMMMnMMM