Let A (-5, 7) be the given point and let P (0, y) be the required point on the y-axis. Then,
PA=13 units⟹PA2=169using the distance formula we can write⟹(0+5)2+(y−7)2=169⟹25+y2−14y+49=169⟹y2–14y+74=169⟹y2–14y–95=0⟹(y−19)(y+5)=0⟹y –19=0 or, y+5=0⟹y=19 or,y=−5Hence,the required points are(0,19) and (0,−5)