find the equation of the set of th points p the sum of whose distance from a [4,0,0] and b is [-4,0,0] is equal to 10
i cannot understand 100-20
how is 20 come ?/

Question

find the equation of the set of th points p the sum of whose
distance from a [4,0,0] and b is [-4,0,0] is equal to 10
i cannot understand 100-20
how is 20 come ?/

Ajanta Trivedi · Accepted Answer

let the coordinates of a point
P(x,y,z) the sum of whose distance from (4,0,0) and (-4,0,0) is
equal to 10
(x-4)2+y2+z2+(x+4)2+y2+z2=10(x-4)2+y2+z2=10-(x+4)2+y2+z2squaring on the both sides , we have:(x-4)2+y2+z2=100+(x+4)2+y2+z2-2*10
(x+4)2+y2+z2⇒(x-4)2-(x+4)2-100=-20
(x+4)2+y2+z2⇒-2*x*4-2*x*4-100=-20
(x+4)2+y2+z2⇒-16x-100=-20 (x+4)2+y2+z2⇒4x+25=5
(x+4)2+y2+z2again squaring on the both sides, we have:(4x+25)2=25
[(x+4)2+y2+z2]
16x2+625+200x=25 [x2+4x+16+y2+z2]16x2+625+200x=25x2+100
x+400+25y2+25z29x2+25y2+25z2-100x+200=0

hope this helps you

find the equation of the set of th points p the sum of whose distance from a [4,0,0] and b is [-4,0,0] is equal to 10i cannot understand 100-20how is 20 come ?/

find the equation of the set of th points p the sum of whose distance from a [4,0,0] and b is [-4,0,0] is equal to 10
i cannot understand 100-20
how is 20 come ?/