Question
The centre of the conic section $$14{x^2} - 4xy + 11{y^2} - 44x - 58y + 71 = 0$$ is :
A.
$$\left( {2,\,3} \right)$$
B.
$$\left( {2,\, - 3} \right)$$
C.
$$\left( { - 2,\,3} \right)$$
D.
$$\left( { - 2,\, - 3} \right)$$
Answer :
$$\left( {2,\,3} \right)$$
Solution :
For centre, $$\frac{{\partial S}}{{\partial x}} = 0,\,\frac{{\partial S}}{{\partial y}} = 0,\,\,\, \Rightarrow 7x - y - 11 = 0,\,\,2x - 11y + 29 = 0.$$ Solve.