Further to my comments of 20 May 2011, the n nth roots of +1, -1, i and -i can be obtained by converting a+ib into an imaginary number by making a equal 0 and substituting Cotes's format cos90+isin90 which equals 0+i. It will be observed that cos180+isin180 equals -1, and cos360+isin360 equals +1 which is i to the power of 4. This system also works for division, cos45+isin45 equals the square root of i.

## Roots of Imaginary Numbers and Unity.

Further to my comments of 20 May 2011, the n nth roots of +1, -1, i and -i can be obtained by converting a+ib into an imaginary number by making a equal 0 and substituting Cotes's format cos90+isin90 which equals 0+i. It will be observed that cos180+isin180 equals -1, and cos360+isin360 equals +1 which is i to the power of 4. This system also works for division, cos45+isin45 equals the square root of i.