| Lefébure de Fourcy (M., Louis Etienne) - Trigonometry - 1868 - 346 pages
...tang } (A + B) a — b tang} (A — B) *• ; which shows that, in any triangle, the sum of two sides **is to their difference as the tangent of half the sum of the angles** opposite to those sides is to the tangent of half their difference. We have A + B=180° — C; hence... | |
| William Mitchell Gillespie - Surveying - 1869 - 550 pages
...to each other at the opposite sides. THEOREM EL — In every plane triangle, the turn of two tides **is to their difference as the tangent of half the sum of the angles** opposite those sides is to the tangent of half their difference. THEOREM III. — In every plane triangle,... | |
| New-York Institution for the Instruction of the Deaf and Dumb - Deaf - 1869 - 698 pages
...we have the principle. When two sides and their included angles are given : The sum of the two sides **is to their difference as the tangent of half the sum of the** other two angles is to the tangent of half their difference. This young man also worked out a problem... | |
| Boston (Mass.). City Council - Boston (Mass.) - 1869 - 1192 pages
...and cosecant. 2. Demonstrate that, in any triangle, the sum of the two sides containing either angle, **is to their difference, as the tangent of half the sum of the** two other angles, to the tangent of half their difference. 8. Given two sides and an opposite angle,... | |
| Charles Davies - Geometry - 1870 - 398 pages
...0 : sin B. Theorems. THEOREM II. In any triangle, the sum of the two sides containing either angle, **is to their difference, as the tangent of half the sum of the** two other angles, to the tangent of half their difference. Let ACB be a triangle: then will AB + AC:... | |
| New-York Institution for the Instruction of the Deaf and Dumb - Deaf - 1871 - 370 pages
...we have the principle. When two sides and their included angles are given : The sum of the two sides **is to their difference as the tangent of half the sum of the** other two angles is to the tangent of half their difference. This young man also worked out a problem... | |
| Elias Loomis - Geometry - 1871 - 302 pages
...^(A+B) . sin. A-sin. B~sin. ^(AB) cos- ^(A+B)~tang. ^(AB) ' that is, The sum of the sines of two arcs **is to their difference, as the tangent of half the sum of** those arcs is to the tangent of half their difference. COS f*fvt Dividing formula (3) by (4), and considering... | |
| Edward Olney - Geometry - 1872 - 472 pages
...observation it horizontal parallax. PLANE TRIGONOMETRY. 80. Ргор.— The sum of any two sides of a plane **triangle is to their difference, as the tangent of half the sum of the angles** opposite is to the tangent of half their difference. ( DEM. — Letting a and b represent any two sides... | |
| Edward Olney - Trigonometry - 1872 - 216 pages
...observation 1s horizontal parallax. PLANE TRIGONOMETRY. 86. Prop.— Tlie sum of any two sides of a plane **triangle is to their difference, as the tangent of half the sum of the angles** opposite is to the tangent of half their difference. DEM. — Letting a and b represent any two sides... | |
| Edward Olney - Geometry - 1872 - 566 pages
...observation 1» horizontal parallax. PLANE TRIGONOMETRY. 86. Prop.— TJie sum of any two sides of a plane **triangle is to their difference, as the tangent of half the sum of the angles** opposite is to the tangent of half their difference. 1 >K\r. — Letting a and b represent any two... | |
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