296 Recent Mathematical Tables Recent Mathematical Tables

In several problems considered in the Antenna Laboratory, Cambridge, Mass., the functions fi(x) = x tan * and/2(ac) = x tanh x have arisen. Tables of these functions with the required range, interval of argument, and number of significant figures apparently do not exist; consequently, such tables were computed specifically to satisfy these needs. They were prepared in the form of reports with the belief that they might prove useful on a much wider basis. A. Values of the function f,(x) are given for x = [0(.001)1.S70; 8D or 8S]. For the computation, values of tan x were taken from NBSCL, Table of Circular and Hyperbolic Tangents and Cotangents for Radian Arguments, New York, 1943. The range is immediately extended to — \ir < x < $x, by observing the identity x tan x = — x tan ( — x). The range may be extended without limit by use of the identity