n>1 n=1 n<1 无法显示该图片。 cccnciad-tencr ne C C2 C CI C2 C C1 C2 C 1 2 1 2 ( ) ( ) ( ) 2 2 C C f C f C f + +  n > 1 n = 1 n < 1 C C C r r r C C2 1 C C2 2 C C1 1 1 2 1 2 ( ) ( ) ( ) 2 2 C C f C f C f + + = 1 2 1 2 ( ) ( ) ( ) 2 2 C C f C f C f + + 