题目内容
设a,b,c∈R+,且a+b+c=1,求证:(a+
证明:左边=
(12+12+12)[(a+
)2+(b+
)2+(c+
)2]≥
(a+
+b+
+c+
)2=
(1+
+
+
)2
=
[1+(a+b+c)(
+
+
)]2?
≥
[1+(
·
+
·
+
·
)2]2?
=
(1+9)2=
.
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题目内容
设a,b,c∈R+,且a+b+c=1,求证:(a+
证明:左边=
(12+12+12)[(a+
)2+(b+
)2+(c+
)2]≥
(a+
+b+
+c+
)2=
(1+
+
+
)2
=
[1+(a+b+c)(
+
+
)]2?
≥
[1+(
·
+
·
+
·
)2]2?
=
(1+9)2=
.