Electronic Proceedings of the Seventh Annual International Conference on Technology in Collegiate Mathematics

Orlando, Florida, November 17-20, 1994

Paper C026

Trigonometric Representation of [x]

David Fung


Department of Mathematics
Southeastern Louisiana University
Hammond, LA 70402
USA
Phone: (504) 549-2175

Steve Ligh


Department of Mathematics
Southeastern Louisiana University
Hammond, LA 70402
USA
Phone: (504) 549-2175


list of all papers by this author


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ABSTRACT

In the software DERIVE (version 2.07), the greatest integer function, [x], when simplify, is given as

[x] = arctan(cot(pi*x))/pi + x - 1/2.

The above equality can be proved by means of properties of trigonometric functions. Using other inverse trigonometric functions, we obtain several forms for [x] as well as other step-liked functions. Moreover, the above equality gives us, among other things, the indefinite integral of [x] as

(2x[x] - [x] - [x]^2)/2 + C.

Keyword(s): Derive, trigonometry, calculus, integrals