The variance o = (X - (X))) of an operator, X, is a measure of how large a range its possible values are spread Vo?). Suppose that |X) is an eigenstate of some operator X, what is the 9. !! over (the standard deviation is given by o = variance of X in this state? You may assume that X) is normalized (X|X) = 1). Note that the expectation value of an operator in the state v) is given by () = ( ). Preview will appear here. Enter math expression here