Let P be the parabola, whose focus is ( − 2 , 1 ) and directrix is 2 x + y + 2 = 0 . Then the sum of the ordinates of the points on P , whose abscissa is -2 , is

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Equation of parabola ( x + 2 ) 2 + ( y − 1 ) 2 = ( 5 ​ 2 x + y + 2 ​ ) 2 5 [ ( x + 2 ) 2 + ( y − 1 ) 2 ] = ( 2 x + y + 2 ) 2 Put x = − 2 , 5 ( y − 1 ) 2 = ( y − 2 ) 2 ​ 5 ( y 2 − 2 y + 1 ) = y 2 − 4 y + 4 ⇒ 4 y 2 − 6 y + 1 = 0 ⇒ y 1 ​ + y 2 ​ = 2 3 ​ ​

Mathematics - Parabola Question with Solution | TestHub

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