1. 定义 设 V 为定义在数域 F 上的向量空间,定义 V 上的线性函数是从 V 到 F 的映射:f:V→F,且满足 ∀x,y∈V,k∈F 有:f(x+y)=f(x)+f(y),f(ka)=kf(a). 现考虑 V 上所有线性函数(f:V→F)的集合 V⋆.对 ∀f,g∈V⋆,x∈V,k∈F,可以在 V⋆ 定义如下的标量乘法和加法(向量加法): 标量乘法:g(kx)=kg(x) 加法:(f+g)(x)=f(x)+g(x)(向量加法,是由定义出来的) 在上述意义下,可以证明 V⋆ 是域 F 上的
摘要 最近更新了一次node,但是更新后npm的命令总是会报 npm WARN deprecated fsevents@2.0.6: Please update: there are crash fixesnpm WARN deprecated text-encoding@0.7.0: no longer maintainednpm WARN deprecated fsevents@1.2.9: One of your dependencies needs to upgrade to fseve
What does "in an effort" to mean? I personally consider in an effort to a stock phrase1. The meaning of the phrase should be clear even when we read it word by word: In an effort to = "In an attempt to" Traditionally, the phrase In an