Find the ratio in which the point (2,y) divides the line segment joining the points (−4,3) and (6,3) and hence find the value of y :
Let the given point C(2,y) divides A(−4,3) and B(6,3) in the required ratio be k:1
Using the section formula −
x = x2k+x1(1)k+1 and y = y2k+y1(1)k+1
Then, 6k−4(1)k+1=2
⇒6k−4=2k+2
⇒6k−2k=4+2
⇒4k=6
⇒k=64
⇒k=32
Hence the ratio is 3:2
Thus, substituting we get the value of y as,
y=3(3)+2(3)3+2
y=9+65
y=155=3
The value of y is 3