当x≤0时, g(x)dx=0-x=0; 当0<x≤1时, 「(x)dx=()d+,m()d 0 Odx+ ldx=x 当1<x时, P(x)dx= (x)dx+Lo(x)dx+L. (x)dy 0 0·dx+1kdx+0x=1 0 7 2021/2/202021/2/20 7 当x0时, ( ) 0 0; x x j x dx dx - - = =   当0<x1时, 0 0 0 0 ( ) ( ) ( ) 0 1 ; x x x x dx x dx x dx dx dx x j j j - - - = + = + =      当1<x时, 0 1 0 1 0 1 0 1 ( ) ( ) ( ) ( ) 0 1 0 1 x x x x dx x dx x dx x dx dx dx dx j j j j - - - = + + = + + =       