... M, N, P Ta cú MN = 2BD, MP = 2CD, NP = 2BC t ú ta cú cỏc tam giỏc AMN, APM, ANP vuụng ti A t x = AM, y = AN, AP = z ta cú x = 2 (a + c b ), y = 2(b + c a ) vy Amax = Cõu V (1.0) z = 2( a + b ... Vy V = 12 (1.0) Cõu VIIa (1.0) D B A N C M 2 (a + c b )(b + c a ) (a + b c ) Gi A l giao im d1 v d2 ta cú A( 3 ;0) Gi B l giao im d1 vi trc Oy ta cú B(0 ; - 4) Gi C l giao im d2 vi Oy ta cú C(0 ... 0.25 Vi x thay vao (2) ta c y = Vi x = log thay vao (2) ta c y = log 2 Kt hp vi iu kin ta c nghim ca phng trỡnh l x = log ,y = log 2 Cõu III x3 t I = ( x e + (1.0) x 1+ x x 1+ x x Ta tớnh I1 =...