| James Morford Taylor - Plane trigonometry - 1904 - 192 pages
...must deduce other formulas, one of which is the law of tangents below. Law of tangents. The sum of any **two sides of a triangle is to their difference as the tangent of half the sum of** their opposite angles is to the tangent of h (1ff their difference. From the law of sines, we have... | |
| William Kent - Engineering - 1902 - 1224 pages
...formulœ enable us to transform a sum or difference into a product. The sum of the sines of two angles **is to their difference as the tangent of half the sum of** those angles is to the tangent of half their difference. sin A + sin В 2 sin ЩА + B) cos WA - B)... | |
| Preston Albert Lambert - Trigonometry - 1905 - 120 pages
...ain(A'-В) = "tan \(A - B) Since a and b are any two sides of the triangle, in words the sum of any **two sides of a triangle is to their difference as the tangent of half the sum of the** opposite angles is to the tangent of half the difference of these angles. The formula a -H1 _ tan £(A... | |
| James Morford Taylor - Trigonometry - 1905 - 256 pages
...must deduce other formulas, one of which is the law of tangents below. Law of tangents. The sum of any **two sides of a triangle is to their difference as the tangent of half the sum of** their opposite angles is to the tangent of half their difference. From the law of sines, we have By... | |
| Plane trigonometry - 1906 - 230 pages
...2 ab cos C These formulas are derived in Appendix ll. 20. Principle of Tangents. — The sum of any **two sides of a triangle is to their difference as the tangent of half the sum of the** opposite angles is to the tangent of half their difference. That is (Fig. 6), ab tan i (A - B) The... | |
| International Correspondence Schools - Building - 1906 - 620 pages
...2 ab cos C These formulas are derived in Appendix II. 20. Principle of Tangents. — The sum of any **two sides of a triangle is to their difference as the tangent of half the sum of the** opposite angles is to the tangent of half their difference. That is (Fig. 6), a + d _ ta a - b ~ tan... | |
| Fletcher Durell - Plane trigonometry - 1910 - 348 pages
...sin В 107 TRIGONOMETRY 75. Law of Tangents in a triangle. In any triangle the sum of any two sides **is to their difference as the tangent of half the sum of the angles** opposite the given sides is to the tangent of half the difference of these angles. In a triangle ABC... | |
| Fletcher Durell - Logarithms - 1911 - 336 pages
...107 sin C' TRIGONOMETRY 75. Law of Tangents in a triangle. In any triangle the sum of any two sides **is to their difference as the tangent of half the sum of the angles** opposite the given sides is to the tangent of half the difference of these angles. In a triangle ABC... | |
| Robert Édouard Moritz - Trigonometry - 1913 - 560 pages
...c- a tan 5 (С - Л) Formulas (7) embody the Law of tangents: In any triangle, the sum of two sides **is to their difference as the tangent of half the sum of the angles** opposite is to the tangent of half their difference. The formulas (6), which we shall have occasion... | |
| Charles Sumner Slichter - Functions - 1914 - 520 pages
...- C) c + a tan KC + A) c - a tan i(C - A) Expressed in words: In any triangle, the sum of two sides **is to their difference, as the tangent of half the sum of the angles** opposite is to the tangent of half of their difference. GEOMETRICAL PROOP: From any vertex of the triangle... | |
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