Question

Shin

求解 136、137

D)
E)
none of these
=11
136. Two vectors have magnitudes of 10 and 15. The angle between them when they are
drawn with their tails at the same point is 65°. The component of the longer vector along
the line of the shorter is:
A) 0
B) 4.2
C) 6.3
D) 9.1
E) 14
137. Let S = (1 m)2 + (2 m)j + (2 m) and T = (3 m)2 + (4 m)k. The angle between these
two vectors is given by:
A) cos ¹(14/15)
B)
cos ¹(11/225)
cos ¹(104/225)
cos ¹(11/15)
cannot be found since S and 7 do not lie in the same plane
138. Two vectors lie with their tails at the same point. When the angle between them is
increased by 20° their scalar product has the same magnitude but changes from positive
to negative. The original angle between them was:
A) 0

Answer 1

youjia

英文不是很好，話說這比較像是數學吧