Question

what is the angle between vector a×b and b×
a​

Answer 1

Explanation:

Due to how the cross product if defined, one of its properties is that A⃗ ×B⃗ =−B⃗ ×A⃗ . This equality shows that A⃗ ×B⃗ and B⃗ ×A⃗ are equal in magnitude but are in in opposite directions. Since they're in opposite directions, the angle between them is 180 degrees.