Plane trigonometry, and its application to mensuration and land surveying. Accompanied with all the necessary logarithmic and trigonometric tables (1852)
Perkins, George R. (George Roberts), 1812-1876 · New York, D. Appleton · leaf 24
cos. 2.cos. 5 = 2 cos. 4 cos. 1—cos. 3.&c. &c. &c. 18.] TRIGONOMETRY. 13 Using the above value of sine and cosine of 1, executing thework above indicated, and preserving only nine decimal places,we find sin. l=O000290888.sin. 2,=0-000581Y76.sin. 3=O000872665.sin. 4=0-001163553.sin.… … § 18. We will now seek formulaswhich shall give the sine and cosineof any arc without our being obligedfirst to compute those of a smallerarc. Denote the arc BC, which meas-ures the angle BAC, by x, the radiusbeing unity. Then assume, CD = sin. x = a0 + ax x + <h ®* + az $ + ai ^ + <% $ +,…
Plane trigonometry · Surveying
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![An illustration from Nicolai Copernici Torinensis De reuolutionibus orbium coelestium, libri VI : Habes in hoc opere iam recens nato, & aedito, studiose lector, motus stellarum, tam fixarum, quàm erraticarum, cum ex ueteribus, tum etiam ex recentibus obseruationibus restitutos: & nouis insuper ac admirabilibus hypothesibus ornatos. Habes etiam tabulas expeditissimas, ex quibus eosdem ad quoduis tempus quàm facillime caculare poteris. Igitur eme, lege, fruere. [Line in Greek] (1543)](https://img.insideoutlibrary.com/img/200/ia-nicolaicopernici00cope-85-61.webp)
