Answer: n = 52
Explanation:
when we have two vectors (x,y) and (a,b) the distance between the vectors is:
D = √( (x - a)^2 + (y - b)^2)
now, we know that:
1) the distance between (x, y ) and the x-axis is 6 units.
The nearest point to (x, y) in the x-axis is the point (x, 0) so we have:
D = 6 = √( (x - x)^2 + (y - 0)^2) = √y^2
so y can be 6 or -6.
So we know that y = 6, and now we can write our point as (x, +-6)
2) The distance between our point and (8, 3) is 5 units:
D = √( (x - 8)^2 + (y - 3)^2) = 5.
And we know that the distance from the origin, (n, n) is:
D = √n = √(x^2 + y^2}
n = x^2 + y^2
Now, we should start with:
√( (x - 8)^2 + (y - 3)^2) = 5
first suppose that y = -6, then:
√( (x - 8)^2 + (-6 - 3)^2) = √( (x - 8)^2 + (-9)^2) = 5.
√( (x - 8)^2 + 81) = 5.
Then we must have that:
and we know that √25 = 5
so (x-8)^2 + 81 = 25
this can never happen, so we can discard y = -6
Now the second case, if y = 6,
√( (x - 8)^2 + (6 - 3)^2) = 5.
√( (x - 8)^2 + (3)^2) = 5.
√( (x - 8)^2 + 9) = 5.
here:
(x - 8)^2 + 9 = 25
(x - 8)^2 = 16
(x - 8) = √16 = +-4
So again we have two cases:
if x - 8 = 4, then:
x = 4 + 8 = 12
but we must have x < 8, so this can be discarded.
now, if x - 8 = -4 then:
x = -4 + 8 = 4, this is an acceptable answer, then our point is (4, 6)
And we have:
n = 4^2 + 6^2 = 16 + 36 = 52