If `((1+i)/(1-i))^m=1,` then find the least positive integral value of `mdot`

Explanation

`((1+ i)/(1-i))^(m) = 1`
or `(((1+i)^(2))/(1-i^(2)))^(m) = 1`
or ` ((1+ i^(2) +2i)/(2))^(m) = 1`
or `i^(m) = 1`
Therefore, the least positive integral value of m is 4.