We notice that the value of E at r naught is negative, as it should be. It's a negative number.

我们主要到在r圈时E的值为负，和它本来的值一致，是一个负数。

麻省理工公开课 - 固态化学导论课程节选

When t is equal to 10,000 years or 10,000 seconds, you're going to find y is some huge negative number.

当t为一万年或一万秒时,我们得到y是一个极大的负数

耶鲁公开课 - 基础物理课程节选