I've tried a few different things for this one, but I can't seem to figure it out.
Could you point in the right direction and tell me what identity I should try to use to figure this one out.
though it would be more adviseable for you to be able to show why
as e^(i*pi) showed.
It's good practice at this stage for you,
and helps you find the calculations getting simpler.
As you say, you found that way easier because it allowed you
to bypass that step using another "less obvious" identity.