... www.thpttamnong.net P NTHITHIHCưNM:2010 ư2011 NIDUNG * TpxỏcnhD=R * Sbinthiờn: ộ x = ưChiubinthiờn:y=4x 10x=2x(2x 5)y=0 ờ x = Ducay: x ưƠ - y + Hmsng bintrờncỏckhong(ư ... GiA(x1y1),B(x2y2).TrngtõmGcatamgiỏcABCcútal: x + x2 - y1 + y -1 G( ). V. 3 CúGthucngthngx+y 2=0nờn: (1im) x1 + x2 - y1 + y - + - = x1 + x2 + y1 + y2 =8 (1). 3 ỡ x = - 2y CúA,Bthucngthng:x+2y 3=0 nờn (2),suyra ợx2 = - 2y2 ... 0,25 0,25 0,25 www.thpttamnong.net ỡ3 x + x - < x< ù Tacú: f '( x)= ù3 x - x < x < ợ Tacúbngbinthiờn : x ư1 f(x) 0 f ' ( x )= x = x = 0,25 + 16 0,25 f(x) ư4 f ( x ) m +15 cúnghim x ẻ [ -1 ...