:which of the following is true about comets in our solar system? a. being mini-stars, they are made of gas. b. they were discovered in the 17th century. c. they take roughly the same amount of time to orbit the sun. d. they all orbit the sun due to the sun’s gravity.

I think the answer is D. I'm sorry if it is incorrect.

i think it because equal matrices have equal dimensions, only square matrices can be symmetric. for all indices and . every square diagonal matrix is symmetric, since all off-diagonal elements are zero. in linear algebra, a real symmetric matrix represents a self-adjoint operator over a real inner product space.

what is the question because that is not a question.