Question

please help me, give me the answer also justify it!
1-angle between (i x j) and -(i x j) is???
a-90
b-30
c-60
(problem related to vectors) thanx!!!

Answer 1

I'm afraid none of the answers is correct.

Answer 2

i x j = k

that's how the whole i,j,k thing is constructed, using the right hand rule convention

and so -(i x j) = -k

Answer 3

means the answer should be 180 degree!

Answer 4

Yep!
Isn't there a typo in your post?