Tns t,d. r-er PHoNG GrAo DUC vA DAo rAo ttpx cuAu on rnr voNG I, cHeN Hec sINH GIoI nuvpN LoP 9 NArvr Hec zot3-zor4 Mdn To6n - (Thdi gian ldm bdi 150 philt) C6u I. (4,0 tliOm) 1.Tinh: a) ,| "' z^,lt +il;' vl-z +2Jj' qJi +3Ja' "" zotzJzon+zlrzJ2lr3' Cdu II. (3,5 di6m) . l. Chimg minh r6ng: a)Niiu a> b>o thi #=;[#-#), 4049 45 CAU III. (5,5 di6m) 1. Giei c5c phucmg trinh sau: a) J*+u+ 6-t6=to; q Jf 4-2J-rs2=0. 2. Chimgminh ring vdi moi x, y ta c6 Uat Aang thric: *o * yo > xyt + x'y . Cffu IV. (5,0 di6m) l. Cho hinh binh hdnh ABCD c6 AC :2A8, M le giao tli6m cua hai ducrng chdo AC vd BD. VE trung tuy6n BE cua tam giirc ABM. a) Chimg minh trEE =frr. b) TU E h4 dudng vudng g6c v6i BM clt BC tai I. Chrmg minh IB : IC. 2. Cho nria dulng tron tdm O duong kinh AB, ban kfnh OC vu6ng g6c vdi AB. Goi d la titip tuy6n v6i nria duong ti'on tai A. Qua di6m M bat k! thuQc cung AC (tru A vd C), ke titip tuytfn v6i dudng trdn, cit dt4i E vh czit dulng thing OC tai D. Goi F ld giao tli6m cria BD va d. Chtrng minh rdng tich AE. kh6ng php thudc vdo vi tri ctadiOm M tr6n cung AC (tru A vd C). CAu V. (2,0 di6m) *. Chung minh ring n6u a, b d€u ld t6ng cua 2 sd chinh phu8ng thi ab cfrng ld ,A ' n A v t6ng cira 2 sd chinh phuong. . cuAu on rnr voNG I, cHeN Hec sINH GIoI nuvpN LoP 9 NArvr Hec zot3-zor4 Mdn To6n - (Thdi gian ldm bdi 15 0 philt) C6u I. (4,0 tliOm) 1. Tinh: a) ,| "' z^,lt +il;' vl-z. zotzJzon+zlrzJ2lr3' Cdu II. (3,5 di6m) . l. Chimg minh r6ng: a)Niiu a> b>o thi #=;[#-#), 40 49 45 CAU III. (5,5 di6m) 1. Giei c5c phucmg trinh sau: a) J*+u+ 6-t6=to; q Jf 4-2J-rs2=0. 2 k! thuQc cung AC (tru A vd C), ke titip tuytfn v6i dudng trdn, cit dt4i E vh czit dulng thing OC tai D. Goi F ld giao tli6m cria BD va d. Chtrng minh rdng tich AE. kh6ng php thudc