证明:1)任取两点x1,x2(x1<x2) 分析:要证∫(+x)<(x)+(x) 2 即证(x)-f(x+)+1(x)-f(x+)>0 x,+x 51∈(x1, f∫(x1)-∫( +32)=f((x-,2)= X+r 352∈( xI+x x一x f(x2)-∫( )=∫(2)(x2 )=∫(2 上一页下一页返回任取两点 , ( ) 证明:1) x1 x2 x1 x2 分析: 要证 2 ( ) ( ) ) 2 ( 1 2 1 x2 x x f x f f + + 即证 )] 0 2 )] [ ( ) ( 2 [ ( ) ( 1 2 2 1 2 1 + + − + − x x f x f x x f x f 2 ) ( ) 2 ) ( )( 2 ( ) ( ), 2 ( , 1 2 1 1 2 1 1 1 2 1 1 2 1 1 x x f x x f x x x f x f x x x − = + = − + − + 2 ) ( ) 2 ) ( )( 2 ( ) ( , ), 2 ( 2 1 2 1 2 2 2 1 2 2 2 1 2 2 x x f x x f x x x f x f x x x − = + = − + − +