.What is the minimum value of the sum of a positive real number and its reciprocal?
问题描述：
.What is the minimum value of the sum of a positive real number and its reciprocal?
RT
答
正实数和它倒数的和的最少值是多少?
设这个正实数为a
那么他的倒数就是1/a
那么a+1/a>=2倍根号（a×1/a)=2
当a=1/a,也就是a=1的时候
取等号
所以正实数和他的倒数的和的最小值是2