CN-LEAGUE 2003 Problem 1

From point $P$ outside a circle draw two tangents to the circle touching at $A$ and $B$ . Draw a secant line intersecting the circle at points $C$ and $D$ , with $C$ between $P$ and $D$ . Choose point $Q$ on the chord $CD$ such that $\angle DAQ=\angle PBC$ . Prove that $\angle DBQ=\angle PAC$ .