Numerical Integral by Gauss Quadrature Using Scientific Calculator

Integration basically refers to anti differentiation. Some simple applications of integration include calculating the area under a curve or volume of curves revolution. There are two main reasons for numerical integration: analytical integration may be impossible or infeasible, and in integrating tabulated data rather than known functions. There are several numerical methods to approximate the integral numerically such as through the trapezoidal rule, Simpson's 1/3 method, Simpson's 3/8 method and Gauss Quadrature method. Solving numerical integral through the Gauss Quadrature method leads to complicated function calculation which may yield wrong results. Hence, there is a need to design a suitable tool in teaching and learning the numerical methods, especially in Gauss Quadrature method. Here, we present a new tip to approximate an integral by 2-point and 3-point Gauss Quadrature methods with the aid of the Casio fx-570ES plus scientific calculator. In doing so, we employed the CALC function into the Casio fx-570ES plus scientific calculator to calculate the complicated function calculation results from Gauss Quadrature method. It is found that the way suggested here is faster than the normal direct calculation and the solution obtained is significantly more accurate. We conclude that the new tip increases the interest of students in learning the numerical integral by Gauss Quadrature method.