Ngày tải lên :
30/07/2014, 15:20
... DABC a) A(1; 2; -3) , B(0; 3; 7), C (12; 5; 0) b) A(0; 13; 21), B(11; - 23; 17), C (1; 0;19) c) A (3; -4; 7), B( -5; 3; -2), C (1; 2; -3) d) A(4; 2; 3) , B(-2;1; -1), C (3; 8; 7) e) A (3; -1; 2), B(1; ... c = (-2; 4; 3) ìa = (5; -3; 2), b = (1; 4; -3) , c = ( -3; 2; 4) rr c) í r r d) í r r r rr rr b u = 4, c u = b u = 9, c u = -4 ỵa.u = 3, ỵa.u = 16, r r r ìa = (7; 2; 3) , b = r4; 3; -5) , c = (1;1; ... (2; 3; 1), b = (1; -2; 0), c = (3; -2; 4) f) a = (5; 4; -8), b = (-2; 3; 0), c = (1; 7; -7) r r r r r r h) a = (2; -4; 3) , b = (-1; 3; -2), c = (3; -2;1) g) a = (2; -4; 3) , b = (1; 2; -2), c = (3; ...