The midpoint (a, b) = (1, -1)
One endpoint, (x₁, y₁) = (3, 8)
The other endpoint, (x₂, y₂) = ?
Using the formula for midpoint and solving for the missing parameters
[tex]\begin{gathered} a=\frac{x_1+x_2}{2} \\ \\ 1=\frac{3+x_2}{2} \\ \\ 2=3+x_2 \\ \\ x_2=2-3 \\ \\ x_2=-1 \end{gathered}[/tex][tex]\begin{gathered} b=\frac{y_1+y_2}{2} \\ \\ -1=\frac{8+y_2}{2} \\ \\ -2=8+y_2 \\ \\ y_2=-2-8 \\ \\ y_2=-10 \end{gathered}[/tex]The coordinates of the other endpoint = (-1, -10)
