## anonymous 4 years ago i^18

1. anonymous

i^18 = 1i^2 = -1

2. anonymous

divide 18 by 4, take the integer remainder. you get 2 because $18=4\times 16+2$ then write $i^{18}=i^2=-1$

3. anonymous

i, -1, -i, 1 is the pattern it goes in. divisible by 4 = 1, divisible by 2 but not 4 = -1

4. anonymous

i^4=1 i^18=i^(4(4)+2) i^4(4)xi^2 1x(-1) =-1