What is exponential integral table?

The exponential integral table is a reference table used in mathematics, engineering, and physics that lists the values of the exponential integral function Ei(z) for various values of z. The exponential integral is a special function that arises in several areas of mathematics and physics, and is defined as the integral of the exponential function e^t/t from t= -∞ to t= z. The exponential integral is commonly used to describe the behavior of electromagnetic fields, quantum mechanics, and statistical mechanics.

The table usually lists the values of Ei(z) for integers and decimal values of z, and provides accurate values of the function to several decimal places. The exponential integral table is widely used in scientific research and engineering applications, where numerical methods may require a large amount of computational resources to calculate the values of Ei(z) accurately. The table is also helpful in solving differential equations, boundary value problems, and other mathematical problems that involve the exponential integral function.