154 Dr Taylor, Geometrical Notes on Theorems 



But In/pn = A M/QM = QM/*a. 



Therefore 



PN.In = AI.QM. 



In what follows Q is to be taken as in the figure and so that 

 the algebraic sum of PN, pn, QM is zero. 



3. Let the normals PG, pg produced meet in a point H whose 

 ordinate is HK, and on AK produced take KJ equal to AT. 

 Then JH will be the normal at Q. 



For In/ IN = pn/PN = KG /Kg, 



the subnormals being each equal to 2a. 



