1 true or false
2 D B D C D B
Simple, do not fight.
4 DE =(-2/3)a+( 1/3)b AD =(2/3)(a+b)BC =( 1/3)(a+b)
EF =(- 1/3)(a+b)FA =( 1/3)a-(2/3)b CD =(2/3)b-( 1/3)a
AB=(- 1/3)b+(2/3)a CE=b-a
8 n=2
14θ= arccos(5/8)β= arccos( 19/20)
Group b
1
2 rectangular diagonal
3 diamond diagonal
4 AM=( 1/2)(a+b)
5 external heart
6 MN=2(b-a) AB is the neutral line.
7 (1) 8KM/H is 60 degrees along the current direction.
(2) 4√2KM/H(90+arccos(√6/3)) along the water flow direction.
8 O is BC OA=0.
I haven't studied the required courses. I don't have to do it.
Which one won't? Just ask me.