In the adjoining figure, TP and TQ are tangents drawn to a circle with centre O. If $\angle OPQ = 15^\circ$ and $\angle PTQ = \theta$, then find the value of $\sin 2\theta$. 
What is the angle between the hour and minute hands at 4:30?
If the given figure shows the graph of polynomial \( y = ax^2 + bx + c \), then: