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 18
Fourth quadrant. … In the above diagrams the dotted lines are considered asnegative and the full lines as positive. The letters in the four diagrams are so arranged that in eachcase BC counted in the positive direction (§ 9) is the arc, CDthe sine, CH the cosine, BE the tangent, GF the cotangent, AEthe secant, and AF…
Plane trigonometry · Surveying
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