Convert the complex number 1+i/1-i in the polar form

1 + i /1-i * 1+i/1+i =(1+i)²/ 1 - i²

1 +i² +2 i /2 

2 i /2 = i 

now we have to show this in polar form i.e 

r{ cos @ + i sin @ }

(mood of r )²= re(z)² +im(z)²
r = 1
 
z = o +i 

then point on (0,1) representing  z = o +i lies on positive direction of imaginary axis therefore angle is pi / 2
 the polar form
 
[ cos pi/2 +i sin pi/2] 
  hope this will help you