∵tanx=2，
则
=3sin2x+2cos2x cos2x?3sin2x
6sinxcosx+2(cos2x?sin2x) cos2x?sin2x?6sinxcosx
=
+2×6sinxcosx sin2x+cos2x
cos2x?sin2x cos2x+sin2x
cos2x?sin2x?6sinxcosx sin2x+cos2x
=
+2×6tanx 1+tan2x
1?tan2x 1+tan2x
1?tan2x?6tanx 1+tan2x
=?
7 15
内容全部来源于网络收集，如有侵权，请联系网站删除：QQ：24596024