 | Harvard University - 1873 - 732 pages
...Obtain the first two formulas used in the previous question, by means of the following equations: — cos a = cos b cos c + sin b sin c cos A, k sin <(> = sin ft cos A, k cos # = cos 6. 7. Given in a spherical oblique triangle, B = 22° 48',... | |
 | Electronic journals - 1882 - 452 pages
...sin2a and transposing, 1 — cos a cos b cos c = sin* a + sin b sin c cos A cos a; (1) also cosM = — cos A cos B cos C -\- sin B sin C cos a cos A, whence 1 + cos A cos B cos C '= sin1 A + sin B sin Ccos acos A. (2) Dividing (2) by (1), we... | |
 | Aaron Schuyler - Measurement - 1875 - 284 pages
...differing more from 90° than another side is of the same species as its opposite angle. By article 136, we have cos a = cos b cos c + sin b' sin c cos A. cos a — cos b cos c cos A = sin 6 sin c But sin 6 sin c is positive, since ¿> and c are each less... | |
 | Henry Nathan Wheeler - Trigonometry - 1876 - 204 pages
...cos AD sin c cos b sin AD . • . cos a = I . cOS AD cOS AD and from [3] tan AD = cos A tan b ; . . . cos a = cos b cos c + sin b sin c cos A, and similarly cos b = cos c cos a + sin c sin a cos B, cos c = cos a cos b + sin a sin 6 cos C. NOTE.... | |
 | Karl Wilhelm Unverzagt - Quaternions - 1876 - 342 pages
...Scalarund Vectortheil. Uebersetzt lautet die Gleichung cos a = cos c cos b + sin c sin b S (oq . obi), oder cos a = cos b cos c -|- sin b sin c cos A, da S (oc, . ob, ) = — cos (n — A) = cos A ist. (II.) Um den SinussUtz sin a : sin b = sin A : sin... | |
 | Rehuel Lobatto - Trigonometry - 1877 - 382 pages
...Sin Q rz — cos B cos C + cos B sin G cotQ. Maar in A DCB , cot Q — cos a <a«^ B zijnde , wordt cos A = — cos B cos C + sin B sin C cos a ; . . (4) zoodat nu, na behoorlijke verwisseling van letters, alle grondformulen terug zijn gevonden.... | |
 | Victor Schlegel - Arithmetic - 1878 - 768 pages
...3) «nb = — -r— — ; 4) sm a sin a Aufgabe 3. — Gegeben bc«. Wenn man in der Formel 336 (a) cos a = cos b . cos c + sin b . sin c . cos a die Substitution macht: (b) cos a — cot b . co< y, so erhält man cos a = cos b (co* C + sin C .... | |
 | Isaac Todhunter - Spherical trigonometry - 1879 - 176 pages
...quadrants. Produce AB and AC to meet at A' ; put = c', A'C = V; then from the triangle ABC, as before, cos a = cos b' cos c' + sin b' sin c' cos A'; but b'-тг — b, c' = тг-c, A' — A; thus cos a = cos 6 cos с + sin 6 sin с cos A. TST (3) Suppose... | |
 | Henry Nathan Wheeler - Plane trigonometry - 1878 - 198 pages
...A', or substituting from above — cos A = (— cos B) (— cos C) + sin B sin C (— cos a) ; or — cos A = cos B cos C — sin B sin C cos a, ) and similarly I r-*r>-, ™ T. ri -ni COS ^ — COS b COS C § 20. From [HI cos A = . — •;—-.... | |
 | Edward Olney - Geometry - 1879 - 502 pages
...(3) of set A' reduce to (2) and (3) of set A". Again, subtracting each member of (1) set B', from 1, we have, cos A + cos B cos C sin B sin C — cos B cos C — cos A — cosa=:l — .-. 2sin'ia = sin B sin C sin B sin C — cos (B + C) — cos A cos... | |
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A'B'C', and applying the law of cosines, we have cos a' = cos b' cos c' + sin b' sin c' cos A'. Remembering the relations a' = 180° -A, b' = 180° - B, etc. (this expression becomes cos A = — cos B cos C + sin B sin C cos a. 
