Academic journal article Mathematics and Computer Education

# Functions of a Spacetime Variable

Academic journal article Mathematics and Computer Education

# Functions of a Spacetime Variable

## Article excerpt

1. INTRODUCTION

Like the familiar complex numbers x + iy, spacetime numbers x + jt are a two dimensional extension of the one-dimensional real numbers x. In our previous paper [2], we explained how to add, subtract, multiply and divide spacetime numbers. We saw that some features of this arithmetic are identical to arithmetic with complex numbers (like addition and subtraction), but other manipulations (like multiplication and division) were very different. In this paper we introduce a subject of importance in applications of mathematics that has previously only been presented at a level appropriate for researchers or graduate students.

We begin with a brief review of key concepts from [2], then introduce the spacetime version of Euler's Formula and use it to represent spacetime numbers. We end by showing how to extend any familiar function of the real variable x to the spacetime variable x + jt. We avoid a rigorous definition-lemma-theorem style in favor of a self-discovery approach. Rigorous presentations are easily found in the references. This paper can be presented to students in calculus, real analysis or complex analysis. The minimum requirement is a familiarity with complex numbers, complex arithmetic, series and Euler's formula for the complex exponential.

Problems are given throughout the paper with selected answers appearing in the final section.

2. REVIEW OF IMPORTANT CONCEPTS IMAGE FORMULA6IMAGE FORMULA7IMAGE FORMULA8IMAGE FORMULA9IMAGE FORMULA10IMAGE FORMULA11IMAGE FORMULA12