e^((i pi)/7) e^(pi i) = e^(i8pi/7) (just add the exponents).
So arg z = 8pi/7 + 2npi (n an integer)
Arg z is the value of arg z that is between -pi and pi. This is 8pi/7 - 2pi = -6pi/7
Say you had a function of:
e^((i pi)/7) e^(pi i)
And you had to find Arg(z),
I'm getting a bit lost, i'm trying to convert it into x + iy form, so i can use tan^-1(y/x) to get the final answer,
so im using e^((8 pi i )/7) = cos(8pi/7) + i sin(8pi/7)
but I can't take it down any further, any help would be appreciated, thanks.
Since the problem asks for the principal argument, there is no need at all for the " ". The principal argument is with n= 0.
Never, ever, convert problems like these to degrees!Let n = -1
So 5pi/6 - 2pi = -210deg?
i also expanded it all, getting tan^-1(x/y) = 5pi/12