Question

For orthonormal basis, which of these is correct?

(a) M^-1 = M^t

(b) M^-1 = M^t

(c) M = M

(d) M^t = I

I have been asked this question in an interview for job.

Question is from Transformations between Coordinate Systems and Affine Transformations topic in section 2D Transformation and Viewing of Computer Graphics

Answer 1

The correct option is (a) M^-1 = M^t

The best I can explain: Due to the effect of similitude and similarity transform, the inverse is equal to the transpose. So, we can say that M^-1 = M^t.