... 17 a = 6a a3 + 6a = Vy f(a) = (a3 + 6a - 5) 2010 = (a3 + 6a + 1)2010 = Cõu (4 ,50 im) 1) (2 ,50 ) iu kin: (x ; y ; z ) 0 ,50 0 ,50 0 ,50 0 ,50 0, 25 Vi iu kin trờn h ó cho tng ng vi h (x y) = ... 1) Thay (4) v (3) vo (2), ta cú 4R2 = 9R 3R 0, 25 0, 25 8kR (k + 9) 5= 3(k + 1) 9( k + 1) 11k + 18k = , gii phng trỡnh c nghim k >0 l k = Vy 0, 25 0, 25 + 11 EB + = EA 11 2) (2,00) Ta cú DH ... ỏn 0, 75 x= 0 ,50 0 ,50 0 ,50 0 ,50 im 1) (2,00) Do AB//CD CDA + DAB = 1800 ; (O,R) l ng trũn ni tip ABCD nờn DO v AO theo th t l phõn giỏc cỏc gúc CDA v DAB ODA + OAD = 0, 25 (CDA + DAB) = 90 0 AOD...