Poats — Isogonic Transformation. 



The equations for the second transformation are 



x 1 — z sin 6 -f- x cos 6 



2/1 = 2/ 



z x — z cos 6 — x sin 

 and equation (6) becomes, after assembling terms, 



47 



as" 



+ cos 2 



— 2 tan a sin 6 cos . „ . _ 



a • 2 a + y 2 + z 2 



+ sm 2 a 



+ 2 tan 2 a sin 2 6 



+ sin 2 (9 



+ 2 tan a sin cos 



+ cos 2 



+ 2 tan 2 a cos 2 



+ 2JC2 



4- sin 6 cos 

 + tan a cos 2 



— tan a sin 2 



— sin 6 cos 



— 2 tan a a sin cos 6 



lz 



= i? 2 . 



(7) 



j^.- 



Fig. 3. 



Making the coefficient of ccjs zero it is found that 



= i(9O°-«) 



