... 11 31 2 2 21 23 1 23 33 0akbaaaakbbbbbbbakb,(,,)ỡ=ù===ạớù=ợ Ã 1122 33 abababab =++rr · 1122 33 0abababab^Û++=rr · 2222 1 23 aaaa=++r · 222 122 aaaa=++r · 1122 33 222222 1 23 1 23 ababababababaaabbb.cos(,)..++==++++rrrrrr ... 23 1120 32 4abc(;;),(;;),(;;)= =-= - rrr f) 548 230 177abc(;;),(;;),(;;) =-= - =- rrr g) 24 31 22 32 1abc(;;),(;;),(;;) =-= - =- rrr h) 2 431 3 232 1abc(;;),(;;),(;;) =-= =- rrr Baøi 13. Tìm ... của DABC. a) 1 23 03 7125 0ABC(;;),(;;),(;;) - b) 0 132 1 11 23 171019ABC(;;),(;;),(;;) - c) 34 7 53 21 23 ABC(;;),(;;),(;;) d) 4 232 1 138 7ABC(;;),(;;),(;;) e) 31 21 211 13 ABC(;;),(;;),(;;)...