Q.

The centre of circle inscribed in square formed by the lines x2-8x+12=0 and y2-14y+45=0, is                       [2003]

1 (4, 7)  
2 (7, 4)  
3 (9, 4)  
4 (4, 9)  

Ans.

(1)

x2-8x+12=0  (x-6)(x-2)=0

y2-14y+45=0  (y-5)(y-9)=0

Hence, sides of square are x=2,x=6,y=5 and y=9

Therefore, centre of circle inscribed in square will be 

(2+62,5+92)=(4,7)