This means that for many sources, destructive interference happens when the first and last wave differ by 360 degrees, a full wavelength λ {\displaystyle \lambda } .
这意味着对於多个波源的情况，第一个波和最後一个波发生相消干涉的条件是相位相差360°，即一个全波长 λ {\displaystyle \lambda } 。