... D 36 Cõu 13 Cho nún cú nh S, ct nún bi mt mt phng qua nh to thnh thit din l tam giỏc SAB Bit khong cỏch t tõm ca ng trũn ỏy n thit din bng 2, AB = 12, bỏn kớnh ng trũn ỏy bng 10 Chiu cao h ca... gia y(C),y(CT) l A.y(C) =2y(CT) B.y(CT) = -y(C) C y (CT ) = y (C) D y (CT ) = y (C) Cõu Bng bin thi n c v l ca hm s no di õy: A y = x x C y = x + 3x B y = x + 3x D y = x 3x Cõu 10. th... x = g ( x), x (, 0) m g ( x) ( ,0) Ta cú: g '( x) = x + = x = g ( x ) = g (1) = V bng bin thi n ta cú m (min ,0) Kt lun: Vi m thỡ iu kin bi toỏn c tha Cõu 21: 21A Gi cnh bờn ca lng tr