Maths Class 11 Chapter 12. Introduction to 3 D Geometry | Page 6

Py = ( my2 + ny1 ) / ( m + n ) =( 2 * 4 + 3 * ( -2 ))/( 2 + 3 ) = 2 / 5
Pz = ( mz2 + nz1 ) / ( m + n ) = ( 2 * ( -5 ) + 3 * 3 )/( 2 + 3 ) = -1 / 5 There coordinates of P are ( 9 / 5 , 2 / 5 , -1 / 5 )
Similarly in case the line is divided externally in ration m : n , then coordinates of Point P are
Px = ( mx2 - nx1 ) / ( m-n ) = ( 2 * 3 - 3 * 1 )/( 2-3 ) = -3
Py = ( my2 - ny1 ) / ( m-n ) =( 2 * 4 - 3 * ( -2))/( 2-3 ) = -14
Pz = ( mz2 - nz1 ) / ( m-n ) = ( 2 * ( -5) - 3 * 3 )/( 2-3 ) = 19 There coordinates of P are ( -3, -14, 19 )