问题
选择题
设正数a、b、c∈R，a+b+c=1，M=(1-
|
答案
∵a+b+c=1，
∴M=(1-
)(1-1 a
)(1-1 b
)1 c
=(
)(a-1 a
)(b-1 b
)c-1 c
=-(
)(b+c a
)(a+c b
)b+c c
≤-(
)(2 bc a
)(2 ac b
)=-8．2 bc c
故选A．
搜题请搜索小程序“爱下问搜题”
设正数a、b、c∈R，a+b+c=1，M=(1-
|
∵a+b+c=1，
∴M=(1-
)(1-1 a
)(1-1 b
)1 c
=(
)(a-1 a
)(b-1 b
)c-1 c
=-(
)(b+c a
)(a+c b
)b+c c
≤-(
)(2 bc a
)(2 ac b
)=-8．2 bc c
故选A．