实数m取什么数值时,复数z=m+1+(m﹣1)i分别是:
(1)实数?
(2)虚数?
(3)纯虚数?
解:(1)当m﹣1=0,即m=1时,复数z是实数;
(2)当m﹣1≠0,即m≠1时,复数z是虚数;
(3)当m+1=0,且m﹣1≠0时,即m=﹣1时,复数z 是纯虚数.
茉莉醛具有浓郁的茉莉花香,其结构简式如下所示:关于茉莉醛的下列叙述错误的是( )
Dear students, please read every sentence carefully. _______ you are, _______ mistakes you'll make.
小球悬挂在细绳下来回摆动,请画出小球在如图位置时所受绳子拉力F和重力G的示意图.