2的负ㄧ次方......1/2 ~(0.5)
2的负二次方......1/4 ~0.25)
2的负三次方......1/8 ~(0.125)
4的负二次方......1/16~0.625 -> 4-2
4的负一次方......1/4~0.25 -> 4-1
n(m-1)
16(2-1) = 4
sqrt(16) = 4
2的负ㄧ次方......1/2 ~(0.5)
2的负二次方......1/4 ~0.25)
2的负三次方......1/8 ~(0.125)
4的负二次方......1/16~0.625 -> 4-2
4的负一次方......1/4~0.25 -> 4-1