Abstract
THIS is, in general, quite a well-written book, though, in some respects, on old lines. It covers elementary trigonometry to the logarithmic solution of triangles, and makes a good beginning by defining the functions of angles of any magnitude with the aid of co-ordinates. Circular measure is also developed early and used frequently throughout the text. If, however, it is deemed necessary to devote a section to the theory and practical use of logarithms, there seems no reason for deferring such to the last chapter, especially when logarithms are freely used from Chapter ii. onwards. The section on the linear equation a cosθ + b sinθ = c is not wholly satisfactory. Greater emphasis should be laid on the introduction of irrelevant roots by squaring than is given in Ex. 2 on p. 108. The method of transforming to a quadratic in tan ½θ does not seem to be dealt with.
Plane Trigonometry.
By Prof. J. B. Rosenbach Prof. E. A. Whitman. Pp. ix + 216. (New York: John Wiley and Sons, Inc. London: Chapman and Hall, Ltd., 1929.) 10s. net.
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Plane Trigonometry . Nature 125, 443 (1930). https://doi.org/10.1038/125443c0
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DOI: https://doi.org/10.1038/125443c0