REPRESENTATION OF A COMPLEX QUANTITY 49 



Case II. Representation of a + W. 



OC = a measured to the left 



BC = b measured vertically upwards 



OB = Va*~+~b* => r 

 /\ 



BOX = = 180 - A in the relation 

 a + bi = r(cos + i sin 0) 



CASE: 2. 



CASE.!. 



CASEl.S. 



FIG. 14. 



Case III. Representation of a bi. 



OC = a measured to the left 

 BC = b measured vertically downwards 

 OB = A/a 2 + b z = r 

 /\ 



BOX = = 180 + A in the relation 

 a - bi = r(cos + i sin 0) 



