 | Horatio Nelson Robinson - 1875 - 288 pages
...71° 50' 48" Here we will apply the following theorem in trigonometry. As the sum of two sides is to their difference, so is the tangent of half the sum of the angles at the base, to the tangent of half their difference. Let x= the half difference between D and... | |
 | William Findlay Shunk - Railroad engineering - 1880 - 362 pages
...opposite to the latter. 3. In any plane trianf/le, as the sum of the sides about the vertical angle is to their difference, so is the tangent of half the sum of the angles at the base to the tangent of half their difference. 4. In any plane triangle, as the cosine... | |
 | Simon Newcomb - Trigonometry - 1882 - 372 pages
...convenient method founded on the following theorem : THEOREM IV. As the sum of any two sides is to their difference, so is the tangent of half the sum of the angles opposite these sides to the tangent of half their difference. Proof. From the equation b : o... | |
 | Royal Society (Great Britain) - Mathematics - 1828 - 490 pages
...the following method : As the tangent of half the sum of the co-latitudes is to the tangent of half their difference ; so is the tangent of half the sum of the observed angles, to the tangent of half their difference. The triangle is thus reduced to a spherical... | |
 | William Findlay Shunk - Railroad engineering - 1890 - 360 pages
...opposite to the latter. 3. In any plane triangle, as the sum of the sides about the vertical angle is to their difference, so is the tangent of half the sum of the angles at the base to the tangent of half their difference. 4. In any plane triangle, as the cosine... | |
 | William Findlay Shunk - Railroad engineering - 1908 - 386 pages
...opposite to the latter. 3. In any plane triangle, as the sum of the sides about the vertical angle is to their difference, so is the tangent of half the sum of the angles at the base to the tangent of half their difference. 4. In any plane triangle, as the cosine... | |
| |
Plane Triangle, As the Sum of any two Sides ; Is to their Difference ; So is the Tangent of half the Sum of the two opposite Angles ; To the Tangent of half the Difference between them. 
