... =−+=+44xyyxyx 8)=+=+23444yxyx 1) (0;2); (2;0) 2) (2; 3),( 3;2), (1 10 ;1 10), (1 10 ;1 10)− − + − − +3) (1; 5),(5 ;1) ,(2;3),(3;2)4) 10 10 10 10 (3; 2),( 2;3),( 2 ; 2 ),( 2 ; 2 )2 2 ... ta có : 1 sin 1 hay sin 1 α α− ≤ ≤ ≤ 1 cos 1 hay cos 1 α α− ≤ ≤ ≤33+−xyOCABD 1 1 1= R 1 1 'x'uut't'yyt'u'ttxu'y'x Ot 1 QBTαMαAPUTrục ... y=log2xxyxyf(x)=ln(x)/ln(2)-4.5 -4 -3.5 -3 -2.5 -2 -1. 5 -1 -0.5 0.5 1 1.5 2 2.5 3 3.5 4 4.5-3.5-3-2.5-2 -1. 5 -1 -0.50.5 1 1.522.533.5xyxy2 1 log= 1 O 1 O a> ;1 y=logax 1 yxO• Chia hai vế của phương...