... hm riờng loi Hyperbolic cú ng dng rt ln khoa hc v thc tin Nh chỳng ta ó bit vic gii cỏc phng trỡnh o hm riờng loi Hyperbolic rt khú khn v phc Nu cú h thng phõn loi bi phng trỡnh Hyperbolic thỡ ... dn gii v phng trỡnh Hyperbolic Chng Mt s kin thc chun b Chng ny nhm gii thiu cỏc khỏi nim c bn v phng trỡnh o hm riờng c bit chỳng ta tỡm hiu v mt i din ca lp phng trỡnh Hyperbolic, ú l phng ... A u = 0, (X , t ) Ê M l phng trỡnh hyperbolic trờn Mn+1 d) Phng trỡnh XU X l X l + U X X + U X = 0,X = (xi,x ) e M2 thuc loi elliptic trờn X i > 0, thuc loi hyperbolic trờn X < v thuc loi parabolic...