... = x - 2x + 2 l: ( - ) ( 2x - 2) A y  = x - 2x + B y  = Luyn thi vo th 3,th 6,ch nht hang tun x - 2x + 2 ( ) - Trang 2/4 - Mó thi 141 C y  = ( 2x - 2) x - 2x + 2 ( ) D  y = ( x - 1) x - 2x... = a , OB = 2a , OC = 3a Th tớch t din OABC l: A a B 2a C 6a D 3a Luyn thi vo th 3,th 6,ch nht hang tun Trang 3/4 - Mó thi 141 Cõu 38: Khi chúp S.ABCD cú ỏy l hỡnh bỡnh hnh Gi B, D ln lt l trung... 1025 D p25 41 A p 1025 Cõu 48: Thit din qua trc ca mt nún l mt tam giỏc vuụng cõn cú cnh huyn bng a Tớnh th tớch nún 1 1 A pa B C D pa pa pa 24 24 Cõu 49: Ngi ta mun thit k mt lng tr t giỏc u cú