Christopher J. answered 05/13/20
Berkeley Grad Math Tutor (algebra to calculus)
The distance between A and B is 6*√5
The equation of the line through A and B is y = -x/2 - 1
We have a ratio of 1:2. Let d be the length of the shorter segment and 2d the length of the longer segment.
The total length is d+2d=3d so 3d= 6*√5 or d=2*√5.
Let M(x,y) be the point we are looking for. Then distance(AM) = 2*√5
But distance(AM)=√(x-(-4))2 + (y-1)2) = √(x-(-4))2 + (-x/2-1-1)2) by the distance formula and substituting y=-x/2-1
solve √(x-(-4))2 + (-x/2-1-1)2) = 2*√5