Roads are banked at turning why

The bank allows a component of the normal force to contribute to the centripetal force.

Banked Turns If the road is banked, so that the outer edge is above the inner edge, then a portion of the normal force from the road on the tires points towards the center of the track; this fraction of the normal force can provide enough centripetal force to keep the car moving in a circle

Explanation:

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.