问题
解答题
证明:tg
|
答案
证明:tg
-tg3x 2
=x 2
-sin 3x 2 cos 3x 2
=sin x 2 cos x 2
=sin
cos3x 2
-cosx 2
sin3x 2 x 2 cos
cos3x 2 x 2
=sinx cos
cos3x 2 x 2 2sinx cosx+cos2x
证明:tg
|
证明:tg
-tg3x 2
=x 2
-sin 3x 2 cos 3x 2
=sin x 2 cos x 2
=sin
cos3x 2
-cosx 2
sin3x 2 x 2 cos
cos3x 2 x 2
=sinx cos
cos3x 2 x 2 2sinx cosx+cos2x