求化简数学公式哦[3sin^2(x/2)+cos^2(x/2)-4sin(x/2)cos(x/2)]/tan(π+x)化简成 (2-2sinx-cosx)/tanx
问题描述:
求化简数学公式哦
[3sin^2(x/2)+cos^2(x/2)-4sin(x/2)cos(x/2)]/tan(π+x)化简成 (2-2sinx-cosx)/tanx
答
原式=3x(cosx-1)/2+(cosx+1)/2 -2sinx
-----------------------------------------------=(2-2sinx-cosx)/tanx
tanx
望采纳,谢谢!
答
原式分子=3sin^2(x/2) - 2sinx + cos^2(x/2)
=3sin^2(x/2) + 3cos^2(x/2) -2cos^2(x/2) - 2sinx
=2 + 1 - 2cos^2(x/2) - 2sinx
=2 - cosx - 2sinx
原式分母= tanx
故原式得到你答案所示.