I would like to find the real and imaginary parts of $x + y$ in terms of polar coordinates.
Here is code:
ComplexExpand[Re[x + y], {x, y}, TargetFunctions -> {Abs, Arg}]
How can I add the assumption that $Abs[x]$ equals to $Abs[y]$?
For example this code does not work:
ComplexExpand[Re[x + y], {x, y}, TargetFunctions -> {Abs, Arg},
Assumptions -> Abs[x] == Abs[y]]