... 11 +0,25oo 6 IA IB 2x 2 IA.IB 12x 1 = = + ị = +0,25yIư1O2ư21xTRNGTHPTCHUYấNTRNPHTTONưTINTHITHIHCLN2NMHC2012ư2013Mụnthi:TONư Khi:A,A1,BThigianlmbi180phỳt,khụngkthigiangiaoPHNCHUNGCHOTTCCCTHSINH ... ]x, y, z 13 ẻ.Tỡmgiỏtrnhnhtcabiuthc:36x 2y zPyz xz xy = + + .1,0 [ ]2 2 22 2 2 236x 2y zf (x) , x 13 ,y,zlthamsụyz zx xy 36 2y z 36x 2y z 36 2.9 9f '(x) 0yzzx x y x yz x yz ... [ ] 2 2 2 2 2 2 2 36 2y z f (x) f (1) g(y), y 1;3 ,z là tham sô yz z y 36 2 z 36 2y z 36 2.9 1 g '(y) 0 z y z y y z y z ³ = + + = Î - + -...