Question 3.b. - http://imgur.com/ztLiRvx
For the sake of simplicity, lets assume that lambda = x.
The Attempt at a Solution
I tried equating the real an imaginary parts of arctan(1/4).
Real: x/2 + 3 = 4. This gives x = 2.
Imaginary: x/2 - 3 = 1. This gives x = 8.
I'm getting two different values of x(lambda).