New plane and spherical trigonometry, surveying, and navigation (1903)
Wentworth, G. A. (George Albert), 1835-1906 · Boston : Ginn & Company · leaf 133
directly above one town, is observedthe angle of depression of anothertown, 10° 14 9. The towns being8 miles apart, find the height of theballoon. Given A = 90° - 10° 14 9 =79° 45 51, a = 8 ; required b.b = a cot A. log a = 0.90309 log cot A = 9.25666 log 6 = 0.15975 b = 1.4446. • Height of… … Let A be the top of the moun-tain, C the object observed, B thecentre of the earth. Then givenB = 90° - A = 2° 13 50, AD = 3 ;required a. BC = AB cos B.a = (a + 3) cos B..-. a (1 — cos B) — 3 cos B.3cos£ By [16], 1 — cos B3 cos B 2 sin2 - log f = 0.17609log cos £ = 9.99967 colog sin2- = 3.42154…
Trigonometry · Surveying · Navigation
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
