Answer
$2cis60^\circ$ and $2cis(-60^\circ)$ are conjugates (As proved in the step by step work)
Work Step by Step
$2cis60^\circ$ = $2(cos60^\circ + isin60^\circ)$
$2cis(-60^\circ)$
= $2[cos(-60^\circ) + isin(-60^\circ)]$
= $2(cos60^\circ - isin60^\circ)$ (since $cos(-\theta) = cos\theta$ and $sin(-\theta) = -sin\theta$)
Hence, $2cis60^\circ$ and $2cis(-60^\circ)$ are conjugates.