Q.

Let S=S1∩S2∩S3, where

S1={z∈ℂ:|z|<4},  S2={z∈ℂ:Im[z-1+3 i1-3 i]>0}, and S3={z∈ℂ:Re(z)>0}.                [2013]

Q.  Area of S=

1 10π3  
2 20π3  
3 16π3  
4 32π3  

Ans.

(2)

S1:x2+y2<16

S2:Im[(x-1)+i(y+3)1-i3]>0

⇒3(x-1)+(y+3)>0 ⇒y+3x>0

S3:x>0

Then S:S1∩S2∩S3 is as shown in the figure given below.

Area of shaded region

=π4×42+π×42×60°360°

=4π+8π3=20π3