Three Space Help

[chee]

need help with a question

Q: determine the point on the y axis equidistant from the points (2, -1, 1) and (0, 1, 3)

i found the midpoint, [1, 0, 2], but then don't know what to do with it after

..help ? D;

 

[Deleted member 4993]

need help with a question

Q: determine the point on the y axis equidistant from the points (2, -1, 1) and (0, 1, 3)

i found the midpoint, [1, 0, 2], but then don't know what to do with it after

..help ? D;

Does that point reside on y-axis?

A point on y-axis would have co-ordinates → [0, y₁ , 0]

Now calculate

the distance d₁ of this point from point (1) [2,-1,1]

and

the distance d₂ of this point from point (2) [0,1,3]

Now equate d₁ & d₂ and find y₁

 

[chee]

Does that point reside on y-axis?

A point on y-axis would have co-ordinates → [0, y₁ , 0]

Now calculate

the distance d₁ of this point from point (1) [2,-1,1]

and

the distance d₂ of this point from point (2) [0,1,3]

Now equate d₁ & d₂ and find y₁

when you say distance do you mean magnitude?

so, sqrt( 2^2 + -1^2 + 1^2) ?

EDIT; oh wait nvm i think i got it..