How Do Calculators Calculate?
We give an introduction to the CORDIC method used my most handheld calculators (such as the ones by Texas Instruments and Hewlett-Packard) to approximate the standard transcendental functions. The CORDIC algorithm does not use Calculus based methods such as polynomial or rational function approximation. The CORDIC (= COordinate Rotation DIgital Computer) algorithm was developed by Jack E. Volder in 1959. His objective was to build a real-time navigational computer for use on aircrafts, so he was primarily interested in computing trigonometric functions. Subsequently, the CORDIC scheme was extended by J. Walther in 1971 to other transcendental functions.
