The graph shows segment \(\overline{AB}\). Point \(P\) divides the segment so that \(AP:PB=1:2\), and point \(Q\) divides it so that \(AQ:QB=2:1\).
a) Find the coordinates of \(P\) and \(Q\).
b) Find the midpoint of \(\overline{PQ}\) and compare it with the midpoint of \(\overline{AB}\).

Hints
- Convert each part-to-part ratio into a fraction of the whole segment measured from \(A\).
- Apply each fraction to the same coordinate change from \(A\) to \(B\).
- After finding \(P\) and \(Q\), use the midpoint formula twice and compare the results.
Solution
a) From the graph, \(A=(-6, 0)\) and \(B=(6, 6)\). Point \(P\) is \(\frac{1}{3}\) of the way from \(A\) to \(B\), so \(P=(-2, 2)\). Point \(Q\) is \(\frac{2}{3}\) of the way from \(A\) to \(B\), so \(Q=(2, 4)\).
b) The midpoint of \(\overline{PQ}\) is \(\left(\frac{-2+2}{2},\frac{2+4}{2}\right)=(0, 3)\). The midpoint of \(\overline{AB}\) is \(\left(\frac{-6+6}{2},\frac{0+6}{2}\right)=(0, 3)\). The two midpoints coincide.
Answer
a) \(P=(-2, 2)\), \(Q=(2, 4)\)
b) Both midpoints are \((0, 3)\).