Question

Point R divides EF¯¯¯¯¯ in the ratio 1 : 5. If the coordinates of E and F are (4, 8) and
(11, 4), respectively, what are the coordinates of R to two decimal places?




(4.66, 7.62)




(6, 6.86)




(5.17, 7.33)




(9.83, 4.67)

Answer 1

Hello,
Let's

$\vec{i}$ the vector unit on ox

$\vec{j}$ the vector unit on oy

$\vec{OE}=4*\vec{i}+8*\vec{j}$
$\vec{OF}=11*\vec{i}+4*\vec{j}$

$\vec{EF}=\vec{OF-\vec{OE}}=(11-4)*\vec{i}+(4-8)*\vec{j}=7*\vec{i}-4*\vec{j}$

$\dfrac{\vec{ER}}{\vec{RF}}=\dfrac{1}{5}$
$5*\vec{ER}=\vec{RF}$==>$5*\vec{ER}+\vec{ER}=\vec{EF}$
$\vec{ER}=\dfrac{\vec{EF}}{6}=\dfrac{7*\vec{i}-4*\vec{j}}{6}$


$\vec{OR}=\vec{OE}+\vec{ER}=4*\vec{i}+8*\vec{j}+\dfrac{7*\vec{i}-4*\vec{j}}{6}=\frac{31}{6}*\vec{i}+\frac{22}{3}*\vec{j}}$

R=(31/6,33/3)≈(5.16,7.33)

Answer C

Answer 2

Answer:

The Answer Is C.

Explanation:

For plato users. Just got a 100 on the test.