1-tan2x≠0 (分母不为0),且2x≠kπ+π/2 (tan2x要有意义)
tan2x≠1,且2x≠kπ+π/2
那么2x≠kπ+π/4,且2x≠kπ+π/2
所以x≠kπ/2+π/8,且x≠kπ/2+π/4 (k∈Z)x≠kπ/2+π/4这步怎么得出来的~求解~谢谢啦~因为tan2x≠1啊……而tan(kπ+π/4)=1，所以2x≠kπ+π/4