Question

Find the co-ordinates of the point of trisection of the line joining the points A(1,8) and B(4,2).

Answer 1

coordinates of the point are (2,6) and (3,4)

Answer:

Solution given:

let the given point be A(1,8) and B(4,2).

P and Q are the two points on AB such that

AP=PQ=QB=k

now

comparing AP and PB

AP=k

PB=2k

ratio of AP and PB =$\frac{1k}{2k}$= ratio 1:2

now

finding p

for this

$(m_1,m_2)=(1,2)$

For AB

$(x_1,y_1)=(1,8)$

$(x_2,y_2)=(4,2)$

now by using division formula

$(x,y)=(\frac{m_1x_2+m_2x_1}{m_1+m2},\frac{m_1y_2+m_2y_1}{m_1+m2})$

$=(\frac{1*4+2*1}{1+2},\frac{1*2+2*8}{1+2})=(2,6)$

similarly

Q divides AB

Ratio of AQ and QB =$\frac{2k}{1k}$= ratio 2:1

$(x_1,y_1)=(1,8)$

$(x_2,y_2)=(4,2)$

$(m_1,m_2)=(2,1)$

by using division formula

$(a,b)=(\frac{m_1x_2+m_2x_1}{m_1+m2},\frac{m_1y_2+m_2y_1}{m_1+m2})$

$=(\frac{2*4+1*1}{2+1},\frac{2*2+1*8}{2+1})=(3,4)$