Calculus trig problem!

f(x)=-4cos(x-3) crosses the y axis at P and the positive side of the x axis for the FIRST time at Q.

1. Find the coordinates of P and Q
2. Find the standard form equation of the tangent to f(x) at Q
3. Find the standard form equation of PQ
4. Find the point on f(x) between P and Q where the tangent to f(x) is parallel to PQ.