How did you arrive at your answer? You noted the repeating pattern:
. . . . .i<sup>0</sup> = 1
. . . . .i<sup>1</sup> = i
. . . . .i<sup>2</sup> = -1
. . . . .i<sup>3</sup> = -i
. . . . .i<sup>4</sup> = 1
. . . . .i<sup>5</sup> = i
. . . . .i<sup>6</sup> = -1
. . . . .i<sup>7</sup> = -i
. . . . .i<sup>8</sup> = 1
...so that every fourth power (i<sup>0</sup>, i<sup>4</sup>, i<sup>8</sup>, etc) returns you to "1". How did you relate this to "i<sup>27</sup> = i<sup>24+3</sup> = i<sup>24</sup> i<sup>3</sup>"?
Thank you.
Eliz.