Army Group X Practice Set 4

According to the question , circlepassed through origin and cuts theintercepts 4 and 2 on X and Y-axes.
From figure,
∠AOB=90°

So, AB is the diameter of circle andA(4,0), B(0,2) are the vertices of circle .
∴ Equation of circle
(x−x1)(x−x2)+(y−y1)(y−y2)=0
⇒(x−4)(x−0)+(y−0)(y−2)=0
⇒x2−4x+y2−2y=0
⇒x2+y2−4x−2y=0