Find the point equidistant from the points P(1,3) and Q(-5,-5), and which lies on the line y=−1.
(-2, -1)
The required point is equidistant from
the points P and Q, and also lies on
the line y=−1.
Let the point be A. Since it lies on y=−1,
its y coordinate will be -1. Thus, the
coordinates of point A will be (x,−1).
Distance AP = Distance AQ
⇒AP2=AQ2
⇒(x−1)2+(−1−3)2 =(x−(−5))2+(−1−(−5))2⇒(x−1)2+16 =(x+5)2+16⇒x2−2x+1+16 =x2+10x+25+16⇒−2x+17=10x+41⇒x=−2
Thus, the coordinates of point A will be (-2,-1).