I.2 m=2+2can2; m= 2-2can2

II.1 x=pi/2+k2pi; x=+-pi/3+k2pi; x=pi+k2pi

II.2 x=6/5

III. can3+ln(7-4can3)/2+2pi/3

IV. V=(3a^3)/2, kc=(a.can3)/2

V. không biết !

VI.a.1 N(0;-2) ; N(6/5;2/5)

VI.a.2 M(-3;-7;13) ; M(5;9;-11)

VII.a z=2-ican3; z= -1-ican3.