Set X has x Members and Set Y has y Members.Set Z consists of all members that are in either Set X o
题目
Set X has x Members and Set Y has y Members.Set Z consists of all members that are in either Set X or Set Y with the exception of the k common members(k larger than 0).which of the following represents the members of members in Set
为什么答案是X+Y-2K
答案
X有x人,Y有y人,Z由所有只单在X,或Y得人,即,除了K个都参加得人组成,Z得人数如何表示?
X+Y得结果是X得人+Y得人,其中,X个人中包含K,y个人中同样包含K,所以要减2K,楼主明白否?
:}
举一反三
已知函数f(x)=x,g(x)=alnx,a∈R.若曲线y=f(x)与曲线y=g(x)相交,且在交点处有相同的切线,求a的值和该切线方程.
我想写一篇关于奥巴马的演讲的文章,写哪一篇好呢?为什么好
最新试题
热门考点