JEE Main202227 Jun 2022Evening ShiftMathematicsParabolaActual
If the equation of the parabola, whose vertex is at 5 , 4 and the directrix is 3 x + y - 29 = 0 , is x 2 + a y 2 + b x y + c x + d y + k = 0 , then a + b + c + d + k is equal to
Options
- A575
- B- 575
- C576
- D- 576
Correct answer
D. - 576
Step-by-step solution
Given the equation of the parabola whose vertex is 5 , 4 and equation of directrix is 3 x + y - 29 = 0 is x 2 + a y 2 + b x y + c x + d y + e = 0 Let focus be α , β Let equation of Z V which is perpendicular to 3 x + y - 29 = 0 be x - 3 y + k = 0 and it passes through point 5 , 4 . So, k = 7 and equation of Z V become x - 3 y + 7 = 0 Now the intersection of 3 x + y - 29 = 0   &   x - 3 y + 7 = 0 will be Z = 8 , 5 Now plotting the diagram we get, So, foot of perpendicular from 5 , 4 on 3 x +