精确解 x2+C1x+C3x∈[0, 2 x2+C2x+C4x∈(,1 ()=0:C3=0,(1 l(1)=0C2+C4=1;,(2)精确解      − + +  − + +  = ,1] 2 1 ( ) 2 1 [0, 2 1 2 4 2 1 3 2 x C x C x x C x C x u (1) 0 1; (2) (0) 0 0; (1) 2 4 3 =  + = =  = u C C u C  