SOLUTION: i^-19= here are my choices 1, -1, i, -i any help would be appreaciated, thanks!

Question 181243: i^-19= here are my choices 1, -1, i, -i
any help would be appreaciated, thanks!
Answer by Mathtut(3670) (Show Source): You can put this solution on YOUR website!
i=i
i^2=-1
i^3=-i
i^4=1
:
so any multiple of i^4=1
:
divide 19 by 4 =4 and 3 left over so
:
= 1(-i)=-i
:
multiply top and bottom by -i=
:
answer is i