Question 96475
{{{i = sqrt(-1) }}}
{{{i^2 = -1 }}}
{{{i^3 = (i)(i^2) }}} giving {{{i^3 = -i }}}
{{{i^4 = (i^2)^2 }}} giving {{{i^4 = (-1)^2 }}} and hence {{{i^4 = 1 }}}


After this, the next powers just return through the same 4 values, so {{{i^5 = i}}} etc.


So, {{{i^10 }}} is the same as {{{i^2}}} which is -1.


Anything as a negative power, like {{{a^(-n)}}} means {{{1/(a^n)}}}, so 1/(-1) is -1. That is your answer.


cheers
jon