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1)

Let E1 Eand FFbe the chords of S passing through the point P(1,1) and parallel to the X-axis and the Y-axis, respectively. Let GG be the chord of S passing through Pand having slope -1. Let the tangents to S at Eand Emeet at E3, then tangents to S at Fand  Fmeet at F3, and the tangents to S at Gand G meet at G3. Then, the points E3, F3, and G3 lie on the curve


A) x+y=4

B) (x4)2+(y4)2=16

C) (x-4)(y-4)=4

D) xy=4

Answer:

Option A

Explanation:

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Equation of tangent at E(3,1) is 

                      3x+y=4  and at  E(3,1)  is

      3x+y=4

Intersection point of tangent at E and E is (0,4)

            Coordinates of Eis (0,4)

Similarly, equation of tangent at F(1,- 3)anf F(1, 3) are x-3y=4 and  x+3y=4 respectively and intersection point is (4 ,0), i.e. , F3 (4,0) and equation of tangent at G1 (0,2) and G(2,0) are 2y=4

and 2x=4, respectively and intersection point is (2,2) ie., G3 (2,2).

      Point    E(0,4) ,F(4,0)   and  G3 (2,2)  satisfies the x+y=4.