Mean number of real zeros of a random trigonometric polynomial. III

If are independent, normally distributed random variables with mean 0 and variance 1, and if is the mean number of zeros on the interval of the trigonometric polynomial , then , in which , , . After tabulation of values of when , the authors find that the approximate formula for , obtained from the above result when the error term is neglected, produces values that are in error by at most when , and by only about 0.1% when .