Solving Complex Analysis Problems - Get Advice Here!

[buzzmath]

Can anyone give me some advice on how to solve this problem?

in the reflection principle if f(x) is pure imaginary then the conjugate of f(z)=-f(z*) where z* is the complex conjugate of z.

Any advice on where to start?

thanks

 

[cristo]

hint: if f is purely imaginary, then one can write f(z)=iy, for some real number, y.