Cindy has five $5coins,three $2 coins and two $1 coins in her purse.
题目
Cindy has five $5coins,three $2 coins and two $1 coins in her purse.
(a)How many$ 2 coins should be added to her purse so that their expected value of a coin randomly chosen from her purse is $3.
答案
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