Question
If the focus of a parabola is $$\left( { - 2,\,1} \right)$$ and the directrix has the equation $$x + y = 3$$ then the vertex is :
A.
$$\left( {0,\,3} \right)$$
B.
$$\left( { - 1,\,\frac{1}{2}} \right)$$
C.
$$\left( { - 1,\,2} \right)$$
D.
$$\left( {2,\, - 1} \right)$$
Answer :
$$\left( { - 1,\,2} \right)$$
Solution :
The vertex is the middle point of the perpendicular dropped from the focus to the directrix.