-3(cosπ/4+isinπ/4)怎么化简?

问题描述:

-3(cosπ/4+isinπ/4)怎么化简?

应该是化成三角形式吧
-3(cosπ/4+isinπ/4)
=3(-cosπ/4-isinπ/4)
=3[cos(π+π/4)+isin(π+π/4)]
=3[cos(5π/4)+icos(5π/4)]
模是3,辐角主值为5π/4