Question 615273
If you start at 0 radians and rotate the radius 8 times by {{{ pi/4 }}}, which is 45 degrees,
you end up back at 0 radians, since {{{ 8*(pi/4) = 2*pi }}}
Now back off {{{ pi/4 }}} radians in the CW direction, and you have {{{ 7*pi/4 }}}
The cotangent is adjacent side / radius which is positive in the 4th quadrant.
So, {{{ cot( 7*pi/4 ) = sqrt(2) / 2 }}}
The rule is just keep adding or subtracting {{{ 2*pi }}} radians, and you will
end up back where you started