Question #07155

2 Answers
Aug 12, 2017

C) 5.17, 7.33

Explanation:

We know if point (x,y) = divides # (x_1, y_1) and (x_2, y_2)# in the ratio of m:n, then the coordinates of (x,y) = #[mx_2+nx_1]/[m+n],[my_2+ny_1]/[m+n].#

Here point R divides E(4,8) and F(11,4) internally. Hence co-ordinates
of R say (x,y) =

# [1.11+5.4]/[1+5], [1.4+5.8]/[1+5]#

= # 31/6 , 44/6#

= 5.1666, 7.33 = 5.17, 7.33

Aug 12, 2017

The answer is option #C=((5.17),(7.33))#

Explanation:

We try a solution with vectors

#vec(ER)=1/6vec(EF)#

#vec(EF)= (((11),(4))-((4),(8)))=((7),(-4))#

Therefore,

#vec(ER)=1/6((7),(-4))=((7/6),(-4/6))#

Coordinates of #R# are

#R=((7/6),(-4/6))+((4),(8))=((31/6),(44/6))=((5.17),(7.33))#