Question

How do I check that I rotated a vector 180° around some axis (like y).
I start with (x,y,z) and after a 180° rotation around the y-axis I got (-x,y,-z) but how do I proof that?

Answer 1

do you want an actual proof or just a way to verify that you did it correctly?

Answer 2

Just a way to verify :)

Answer 3

ok

Answer 4

a 180 degree rotation is multipling by -1