线性无关正交化、单位化 B1 a1-∑(an,月) i=2,3. ∑(an,月1) k=(a,月k1=a1或kn圳a1∑(a,月)B‖正交化、单位化 1 1 1 1 1 1 1 || || ( , ) 2, 3, , || ( , ) || i i i j j j i i i i j j j a a a a i n a a       − = − =  =      −   = =  −     1 11 1 1 ( , ), || || || ( , ) || i ij i j ii i i j j j k a k a k a a    − = = = = − 或  a1 , a2 ,  , an 线性无关