已知a>0,b>0,c>0.则a2+b2+c2ab+3bc的最小值为______

已知a>0,b>0,c>0.则a2+b2+c2ab+3bc的最小值为______.
2025-06-23 01:59:12
推荐回答(1个)
回答1:

∵a2+b2+c2=a2+

1
10
b2+
9
10
b2+c2
=(a2+
1
10
b2)+(
9
10
b2+c2)
≥2
a2?
1
10
b2
+2
9
10
b2c2

=2
1
10
ab+6
1
10
bc
=
10
5
(ab+3bc)

a2+b2+c2
ab+3bc