1/10指对运算一.指数运算(1)分数指数幂与根式的互化1
mmnnaa2
mnmnaa(2)指数的运算法则(1)0,,
srsrsrrsrrraaaarsRaaarsRabababrR二.对数运算(1)对数恒等式loglog10,log1,,log
aNbaaaaaNab(2)对数的运算法则(010,0,aaMNR且,)loglogloglogloglogloglogaaaaaaaaMNMNMMMMNN(3)换底公式loglog,0,1,0logcacbbacacba且2/10lglnloglglnloglogloglog1aaaabbbbaabbba推论:习题集锦一.选择题(共8小题)1.化简326(0)xxxx的结果是A.xB.2xC.1D.x2.已知1x,则2(1)(xA.1xB.1xC.1xD.1x3.若2lga,3lgb,则5log12等于A.21abaB.21abaC.21abaD.21aba4.已知a,s,都是正实数,且1a,下列运算一定正确的是A.ststaaaB.ststaaaC.logaloglog()aaststD.logloglog()aaastst5.计算516(log4)(log25)(A.2B.1C.D.6.32log4333270
01(lglne3/10A.14B.0C.1D.67.若0x,0y,*nN,则下列各式中,恒等的是A.lgxlgylgxlgyB.22()lgxlgxC.1nlnxlnxnD.lnxxlnnn8.若lgxlgya,则33()()(22xylglgA.3aB.32aC.aD.二.解答题(共7小题)9.计算下列各式的值:(1)2320341168()()(2020)281;(2)7log522258520(2)73lglglglglg.4/1010.计算以下式子的值:(1)2225lglg