IV. TIEN TDM DAY HOC
MQT SO Bfll TflP TRflC NGHIEM
Cau 1 .• Cho 3 diem A, B, C. Ta cd :
(a) AB + JC = W; (c) 'AB-¥C = ^ ;
Trd ldi: Phuang an (d) diing.
(b) AB-AC = BC
(6) AC-BC = AB
Cau 2 .• Cho 4 diem A, B, C, D. Ta cd dang thiic sau :
(a) AB-CD = AC-BD; (b) AB + CD = AC + BD
(c) AB = CD + DA + BA;
Trd ldi: Phuang an (a) diing.
Cau 3 .• Neu tam giac ABC cd
(a) Tam giac vudng tai A ; (c) Tam giac vudng tai C ;
Trd ldi: Phuong an (c) diing.
(d) AB + AC = DB + DC
CA + CB CA-CB thi tam giac ABC la (b) Tam giac vudng tai B ; (d) Tam giac can tai C.
§4. Tich cua mot vector vdi mot so (tiet 8, 9,10,11) (tiet 8, 9,10,11)
1. MUC Tl!u 1. Kien thurc
,1. Hpc sinh ndm dupe dinh nghia tich cua mdt vecta vdi mdt sọ Khi cho mdt sd k
cu thi va mdt vecto a cu the, cac em phai hinh dung ra dupe vecto ka nhu the
nao (phuang, hudng va dp dai cua vecta đ).
2. Hpc sinh hieu dupe cac tinh chat cua phep nhan va ap dung trong cac phep tinh.
3. Ndm dupe y nghia hinh hpc eua phep nhan : hai vecto a va b cung phuang (a khac vecto 0) khi va ehi khi cd sd k sao cho b=kạT\t66 suy ra dieu kien de ba
diem thdng hang. 2. KT nang
• Thuc hanh tdt viec chiing minh ba diem thang hang. • Biet phan tich mdt vecta thanh to hpp cua cac vecto khac.
• Chiing minh dupe mdt so bai toan cd lien quan den trung diem, trpng tam. 3. Thai do
• Lien he duoc vdi nhi6u ván d6 cd trong thuc te vdi van 66 w6 tich cua mdt vecta
vdi mdt sd.
• Co mdi lien he chat che giiia tdng, hieu hai vecto vdi tich mdt sd va mdt vectạ