Question

Check whether the 3 vectors ar coplanar or not
A= t+j+k , B= i+3j+k , C= 2i+2j+2k

Answer 1

If three vectors are coplanar, their scalar triple product is zero. Give it a go, and someone will check your work :)

Answer 2

I assume you mean A = i+j+k
Is A X B in the same direction as A X C?
You can work it out but by inspection you can see that vector A is the same direction as vector C and therefore, A and B (or C and B) define a plane.

Answer 3

No it's A = t+j+k

Answer 4

well, we know they are coplanar if t = 1
not if not

Answer 5

Thanks .. thats what i was doubtful about !!!

Answer 6

well it is very difficult for A to be perpendicular to both B and C otherwise
because j + k and 3 j+k just do not work :)