$3\mathrm{.}23.$ Find the angular velocity of link $7$ and the linear velocity of point $F$ on the slider of the eight$-$bar linkage in Fig. P$3\mathrm{.}31$; ${}_2=1ra\frac{d}{secccw}.$

$($a$)$ Use the relative velocity method.

$($b$)$ Use the instant$-$center method.

$($c$)$ Use complex$-$number arithmetic.

Figure P$3\mathrm{.}31$