Evaluating the Probability Integral Using Wallis's Product Formula for π.

The article discusses the evaluation of the probability integral using the product formula for π of mathematician John Wallis. It explores the standard one-variable calculus method for evaluating the probability integral and functions using the approximation theory. It states that to approximate the integrand in the probability integral can yield a simpler evaluation of integrals. It proves that calculating the limits of the expression can be done using the Wallis product formula for π.