Q.

Let z1 and z2 be two complex numbers such that |z1|=1 and |z2|=10. If θ=arg(z1-z2z2) then maximum value of tan2θ is

1 110  
2 1100  
3 199  
4 1099  

Ans.

(3)

Put z1z2=z

∴ |z1z2|=|z|⇒|z|=110

Also, θ=arg(z1z2-1)=arg(z-1)

∴  tan2θmax=1/10099/100=199