# The Principles of Analytical Geometry: Designed for the Use of Students

J. Deighton & Sons, 1826 - Geometry, Analytic - 326 pages

### Popular passages

Page 7 - AB be the given straight line ; it is required to divide it into two parts, so that the rectangle contained by the whole, and one of the parts, shall be equal to the square of the other part.
Page 1 - In every triangle, the square on the side subtending either of the acute angles, is less than the squares on the sides containing that angle, by twice the rectangle contained by either of these sides, and the straight line intercepted between the acute angle and the perpendicular let fall upon it from the opposite angle, Let ABC be any triangle, and the angle at B one of its acute angles, and upon BC, one of the sides containing it, let fall the perpendicular AD from the opposite angle.
Page 244 - B . sin c = sin b . sin C cos a = cos b . cos c + sin b . sin c cos b = cos a . cos c + sin a . sin c cos A cos B cos c = cos a . cos b + sin a . sin b . cos C ..2), cotg b . sin c = cos G.
Page 116 - Fig. 83,84. conjugate diameters is equal to the sum of the squares of the...
Page 66 - The lines drawn from the angles of a triangle to the middle points of the opposite sides meet in a point.
Page 115 - ... of the squares of any two conjugate diameters is equal to the difference of the squares of the axes.
Page 14 - Three lines are in harmonical proportion, when the first is to the third, as the difference between the first and second, is to the difference between the second and third ; and the second is called a harmonic mean between the first and third. The expression 'harmonical proportion...
Page 68 - Find an expression for the area of a triangle in terms of the coordinates of its angular points.
Page 79 - If two chords intersect in a circle, the difference of their squares is equal to the difference of the squares of the difference of the segments.
Page 253 - It will be demonstrated art. 452, that every section of a sphere made by a plane is a circle.