Please help
give real-world examples of how the body responds to stimuli.

Some real world examples of how the body responds to stimuli are:

External stimuli: something is coming at your face and you flinch or blink, you see a car coming at you so you dive out of the way, you are enjoying an activity and so your body releases dopamine.

Internal stimuli: you are hungry and signals respond to stimulus and send signals to your brain,

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.