Given that and , where z is not 6 . If w is totally imaginary , show that
Hello again mathaddict.
Are you sure you have copied down the question correctly?
I think the expression should be .
You then:
- Replace by in the top and bottom
- Collect together reals and imaginaries on the top and on the bottom
- Multiply top and bottom by , which is the conjugate of the bottom
Don't multiply everything out at this stage. Just find the real part of the top. This must be zero if w is wholly imaginary. This will then give you
Grandad