{(1-3i)的三次方}的虚部是什么

题目

{(1-3i)的三次方}的虚部是什么

答案

(1-3i)³
=1³-3×1²×3i+3×1×(3i)²-(3i)³
=1-9i+3×1×(-9)-(-27i)
=-26+18i
所以虚部是18