All vectors are in rn. check the true statements below:

a. not every orthogonal set in rn is a linearly independent set.

b. an orthogonal matrix is invertible.

c. if the columns of an m×n matrix are orthonormal, then the linear mapping x? .

d. if a set s={} has the property that ui? uj=0 whenever i? j, then s is an orthonormal set.

e. the orthogonal projection of y onto v is the same as the orthogonal projection of y onto cv whenever c? .