State the degree:
rst+r^2s^2+r^3s^2

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.

it is very well related to a lot of things but with my limited knowledge i can confidently say that the answer is space.