Question 12 Marks
If A and B are (-2, -2) and (2, -4) respectively, find the coordinates of P such that AP = $\frac{3}{7}$ AB and P lies on the line segment AB.
Answer
View full question & answer→A = (-2, -2) and B=(2, -4)
It is given that AP= $\frac{3}{7}$ AB
PB = AB - AP = AB −$\frac{3}{7}$AB = $\frac{4}{7}$AB
So, we have AP:PB = 3:4
Let coordinates of P be (x, y)
Using Section formula to find coordinates of P, we get
$x = \frac{{( - 2) \times 4 + 2 \times 3}}{{3 + 4}} = \frac{{6 - 8}}{7} = \frac{{ - 2}}{7}$
$y = \frac{{( - 2) \times 4 + ( - 4) \times 3}}{{3 + 4}} = \frac{{ - 8 - 12}}{7} = \frac{{ - 20}}{7}$
Therefore, Coordinates of point P are $\left( {\frac{{ - 2}}{7},\frac{{ - 20}}{7}} \right)$.
It is given that AP= $\frac{3}{7}$ AB
PB = AB - AP = AB −$\frac{3}{7}$AB = $\frac{4}{7}$AB
So, we have AP:PB = 3:4
Let coordinates of P be (x, y)
Using Section formula to find coordinates of P, we get
$x = \frac{{( - 2) \times 4 + 2 \times 3}}{{3 + 4}} = \frac{{6 - 8}}{7} = \frac{{ - 2}}{7}$
$y = \frac{{( - 2) \times 4 + ( - 4) \times 3}}{{3 + 4}} = \frac{{ - 8 - 12}}{7} = \frac{{ - 20}}{7}$
Therefore, Coordinates of point P are $\left( {\frac{{ - 2}}{7},\frac{{ - 20}}{7}} \right)$.



Let coordinates of the required point be R(x, y). This means R divides the join of P(4, -3) and Q(8, 5) in the ratio 3:1 internally.