... ca nc bin H th hai c gi l h to sigma, (x*, y*, s) vi x*=x, y*=y v s = z h ( x, y ) , ú H(x,y) l sõu a hnh v h(x,y) l mc bin (h=0 tng ng H ( x, y ) h ( x, y ) cho mt bin c nh Cỏc phng trnh ... cng nh x lý iu kin trn mt bin Phõn loi theo to thng ng li z (z-C) li to sigma (- C) li ng th (- C) Hỡnh 7. 1 Cỏc s li to thng ng Hnh 7. 1 cho ta s cỏc h to thng ng khỏc H th nht c gi l h to ... dng cỏc phng trnh bin i tớch phõn v cỏc ụ li th tớch li thng hay cu (RS) Li trc giao cong (CO) Li khụng trc giao cong (NO) Hỡnh 7. 2 S cỏc dng li tớnh Mt c im khỏc cho phộp phõn bit cỏc mụ hnh ú...