15. The centre of circle inscribed in square formed by the lines $x ^ { 2 } - 8 x + 12 = 0$ and $y ^ { 2 } - 14 y + 45 = 0$, is: (a) $( 4,7 )$ (b) $( 7,4 )$ (c) $( 9,4 )$ (d) $( 4,9 )$
The range of the function $f ( x ) = \frac { x ^ { 2 } + x + 2 } { x ^ { 2 } + x + 1 } , x \in ( - \infty , \infty )$ is
15. The centre of circle inscribed in square formed by the lines $x ^ { 2 } - 8 x + 12 = 0$ and $y ^ { 2 } - 14 y + 45 = 0$, is:\\
(a) $( 4,7 )$\\
(b) $( 7,4 )$\\
(c) $( 9,4 )$\\
(d) $( 4,9 )$\\