... (S1) : x 2 +y 2 +z 2 - 6x+4y-2z - 86 = 0.(S 2 ) : x 2 +y 2 +z 2 +6x-2y-4z -2 = 0. vµ (P) : 2x-2y-z +9 = 0.1. X¸c ®Þnh t©m cđa ®êng trßn lµ giao cđa (P) vµ (S1). 2. Cmr (S1) vµ (S 2 ) c¾t ... xdx∫ 16, 2 1xdxe−+∫ 17 2 2 1 3x x dx+∫ 18, 3 2 1x x dx+∫ 19, 17 9 2 3x x dx−∫ 20 , 2 1xdxx+∫ 21 , 2 1 xdxx−∫ 22 , 2 2dxa x+∫ 23 , 2 2 7dxx x+ +∫ 24 , 2 2 5dxx ... đỉnh A, B, C, D a)A(1; 2; -3 ), B(0; 3; 7), C( 12; 5; 0), D (9; -6 ; 7)b)A(0; 13; 21 ), B(11; -2 3; 17), C(1; 0; 19) , D ( -2 ; 5; 5)Câu 7:Cho A(3; -4 ; 7), B (-5 ; 3; -2 ), C(1; 2; -3 )a)Xác định D sao cho...