Poats — Isogonic Transformation. 



The equations for the second transformation are 

 x 1 = z sin -\- x cos 



47 



« = u cos — x sin 



and equation (6) becomes, after assembling terms, 



x' 



+ cos 2 



— 2 tan a sin cos 



+ 2/ 2 + z 2 



+ sin 2 <9 



+ 2 tan 2 a sin 2 



+ sin cos 



+ sin 2 



+ 2 tan a sin cos 



+ cos 2 



+ 2 tan 2 a cos 2 



+ 2#z 



+ tan a cos 2 



— tan a sin 2 



— sin cos 



— 2 tan 2 a sin cos 



= i? 2 . 



(7) 



Fig. 3. 



Making the coefficient of xz zero it is found that 



= s(90°-«) 



