px+qy=6 qx−py=2 and x2+y2=4 From the above equation, it is clear that the value of x=√2 and y=√2 . So, p√2+q√2=6 p+q=3√2……(i) and q√2−p√2=2 q−p=√2……(ii) Squaring both sides of equation (i) and (ii) and then adding, we get: p2+q2=10