Assume that   is an orthonormal basis of  and the vector has in this basis coordinates . In the field provided, enter the numerical value of

Assume that ,   and   is an orthonormal basis of and . Which of the below can be the coordinate vector of in this basis:

Choose all vectors from the list below that are orthogonal to the two vectors and 

Assume that is a -dimensional subspace of and is the matrix of the orthogonal projector of  onto . Which of the statements below are always true?