｜1+√3i｜-｜z｜≤｜1+√3i+z｜≤｜1+√3i｜+｜z｜
即0≤｜1+√3i+z｜≤4
当z=-（1+√3i）时,｜1+√3i+z｜取最小值
当z=1+√3i 时,｜1+√3i+z｜取最大值