The question and what I've done so far:
The blue bit is from the mark scheme - but I don't understand how they have come to this
And the red bits are 'rules' we can use for modulus
I've written out the complex and the complex conjugate but not sure what to do!
Complex modulus proof watch
- Thread Starter
- 08-04-2013 01:21
- 08-04-2013 01:38
Well first, sub in z= r ( cosθ + i sinθ ) into the modulus. Then simply take the modulus of the thing which is root of real part squared plus imaginary part squared (the root goes away because the modulus is squared in the question) . So your real part is rcosθ + 1 and imaginary part is -rsinθ. Then just expand the brackets.
This is the same as finding the modulus of eg : 3 + 2i. you would do √ 3^2 + 2^2. you are doing the same thing hereLast edited by thephysicsguy; 08-04-2013 at 01:42.
Last edited by Hasufel; 08-04-2013 at 01:50.
- 08-04-2013 01:45