The equation of the parabola whose focus is (1, - 1) and the directrix is x + y + 7 = 0 is

Given that we need to find the equation of the parabola with focus (1, - 1) and directrix x + y + 7 = 0



Let us assume P(x, y) be any point on the parabola.


We know that the point on parabola is equidistant from focus and directrix.


We know that the distance between two points (x1, y1) and (x2, y2) is .


We know that the perpendicular distance from a point (x1, y1) to the line ax + by + c = 0 is .


SP = PM


SP2 = PM2




2x2 + 2y2 - 4x + 4y + 4 = x2 + y2 + 49 + 2xy + 14x + 14y


x2 + y2 - 2xy - 18x - 10y - 45 = 0


The correct option is D

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