由于|a+b|在a、b同号时值最大,故可设a>0,b>0(a、b小于0时结果一样);
(a*a+1)(b*b+1) =a²b²+a²+b²+1=a²b²+(a²-a+1/4)+(b²-b+1/4)+a+b+1/2
=a²b²+(a-1/2)²+(b-1/2)²+a+b+1/2>a+b=|a+b|
若a
由于|a+b|在a、b同号时值最大,故可设a>0,b>0(a、b小于0时结果一样);
(a*a+1)(b*b+1) =a²b²+a²+b²+1=a²b²+(a²-a+1/4)+(b²-b+1/4)+a+b+1/2
=a²b²+(a-1/2)²+(b-1/2)²+a+b+1/2>a+b=|a+b|
若a