If M is the midpoint of AB, A (0,4) and M (3,-2), find the coordinates of B.

Answer 1

The distance from A to M is SQRT(45). and the equation of the line is y = -2x + 4.

Next find the distance between M(3,-2) and B(x₃,y₃) or B(x₃, -2x₃ + 4)

When you substitute into the distance formula with x₃ as the unknown & set both to SQRT(45),

You get x₃ = 6. Substituting into y₃ = -2x₃ + 4, you get y₃ = -8.