问题
填空题
已知lga+lgb=0,则
|
答案
把条件转化为ab=1,
∴
+b 1+a2
=a 1+b2
+b2 b+a2b
=a2 a+ab2
+b2 b+a a2 a+b
=
=a2+b2 a+b
≥2(a2+b2) 2(a+b)
=a2+b2+2ab 2(a+b)
=(a+b)2 2(a+b)
≥a+b 2
=1,ab
故答案为:1.
已知lga+lgb=0,则
|
把条件转化为ab=1,
∴
+b 1+a2
=a 1+b2
+b2 b+a2b
=a2 a+ab2
+b2 b+a a2 a+b
=
=a2+b2 a+b
≥2(a2+b2) 2(a+b)
=a2+b2+2ab 2(a+b)
=(a+b)2 2(a+b)
≥a+b 2
=1,ab
故答案为:1.