$(8$ marks$)$ Prove that your point X

is correct by showing that

d$($x$,$p$)=4$d$($x$,$q$)$

Note: The distance d$($A$,$B$)$

between points A

and B

in Rn

is the same as the distance between the vectors a$=$OA$->$

and b$=$OB$->$

$,$ that is$,$ d$($A$,$B$)=$d$($a$,$b$)=\backslash |$ a$$b$\backslash |$

$.$