1/9 (7 - 2^m E^(I m \[Pi]) (7 + 3 m))
1/9 (7 - (-2)^m (7 + 3 m))
I tried using the following method myself:
expr = 1/9 (7 - 2^m E^(I m \[Pi]) (7 + 3 m));
expr /. E^(I m \[Pi]) -> (-1)^m // Simplify
My current requirement is: without using manual identification and substitution methods, what other methods can automatically replace the Euler's formula part in it with -1?
