Let PS be the median of the triangle with vertices P(2,2), Q(6,-1) and R(7,3).

Question

Let $PS$ be the median of the triangle with vertices $P(2,2),\ Q(6,-1)$ and $R(7,3)$. The equation of the line passing through $(1,-1)$ and parallel to $PS$ is:

Accepted Answer

$S$ = midpoint of $QR = \left(\dfrac{6+7}2,\dfrac{-1+3}2\right)=\left(\dfrac{13}2,1\right)$.

Slope of $PS = \dfrac{2-1}{2-\frac{13}2} = \dfrac1{-9/2}=-\dfrac29$.

Line through $(1,-1)$ with slope $-\dfrac29$:
$$y+1=-\frac29(x-1) \implies 9y+9=-2x+2 \implies 2x+9y+7=0$$

Solutions · 1