Question

均值不等式习题 三个数,a

Answer 1

1/a+1/b+1/c=-(1/a+1/b+1/c)*(a+b+c)

=-(1+1+1+b/a+a/b+c/a+a/c+c/b+b/c)

=-(3+b/a+a/b+c/a+a/c+c/b+b/c)

因为a小于0,b小于0,c小于0

所以b/a+a/b>=2, 当且仅当a=b时取等号

c/a+a/c>=2 当且仅当a=c时取等号

c/b...