If C⃗ = -5 i^ - 3 j^ - 4 k^, what is C⃗ × j^?

Answer 1

+i +j +k
-5 -3 -4
+0 +1 +0

= 5 k + 4 i
or
4i +0j +5k

(note obviously perpendicular to j so no j component)