1、自我小测1下列各式成立的是()Atan()tan Btan()tan Ctan()tan Dtan(2)tan 2tan的值为()A B C D3已知角终边上有一点P(5n,4n)(n0),则tan(180)的值是()A B C D4已知tan(243),那么tan(927)的值为()A B C3 D35化简tan()tan()的结果为()A0 B2tan C2tan D2cot 6tan_.7已知tan(x),则tan(x3)_.8log4sinlog9tan_.9求下列各式的值:(1)costan;(2)sin 810tan 765tan 1 125cos 360.10利用正切函数的单调性
2、比较tan与tan的大小参考答案1解析:tantantan5,故tan5.答案:B2解析:btan 2tan(2),ctan 3tan(3),又231,且ytan x在上是增加的,则有tan(2)tan(3)tan 1,即bca.答案:B3解析:tantantantantan.答案:4解析:tan 300tan 60.答案:5解:(1)tan 9tan(29),而229,且ytan x在内是增加的,tan 2tan(29),即tan 2tan 9.(2)tantan,tantan,又0,且ytan x在内是增加的,tantan,即tantan.课后作业稳步提升1解析:tan()tan ;tan
3、()tan ;tan()tan ;tan(2)tan()tan .故选C.答案:C2解析:tantantan.答案:B3解析:角终边上有一点P(5n,4n)(n0),tan ,tan(180)tan .答案:A4解析:tan(243)tan(18063)tan(63),而(27)(63)90,所以tan(27)3,所以tan(927)tan(927)tan(518027)tan(27)3.答案:C5解析:tan()tan()tan tan 0.答案:A6解析:tantantantantantan.答案:7解析:由tan(x)知tan x,故tan(x3)tan(3x)tan x.答案:8解析:sinsinsin,tantantan,log4 sinlog9 tanlog4log9.答案:9解:(1)costancostancostan1.(2)原式sin(236090)tan(236045)tan(336045)cos(0360)sin 90tan 45tan 45cos 04.10解:tantantan,tantantan,又函数ytan x在上是增加的,而,tantan,即tantan.