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-3(cosπ/4+isinπ/4)怎么化简?

题目详情
-3(cosπ/4+isinπ/4)怎么化简?
▼优质解答
答案和解析
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