Circle 1 Question 24

24. Let E1E2 and F1F2 be the chords of S passing through the point P0(1,1) and parallel to the X-axis and the Y-axis, respectively. Let G1G2 be the chord of S passing through P0 and having slope -1 . Let the tangents to S at E1 and E2 meet at E3, then tangents to S at F1 and F2 meet at F3, and the tangents to S at G1 and G2 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) (x4)(y4)=4

(d) xy=4

Show Answer

Solution:

Equation of tangent at E1(3,1) is

3x+y=4 and at E2(3,1) is 3x+y=4

Intersection point of tangent at E1 and E2 is (0,4).

Coordinates of E3 is (0,4)

Similarly, equation of tangent at F1(1,3) and F2(1,3) are x3y=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 G2(2,0) are 2y=4 and 2x=4, respectively and intersection point is (2,2) i.e., G3(2,2). Point E3(0,4),F3(4,0) and G3(2,2) satisfies the line x+y=4.



NCERT Chapter Video Solution

Dual Pane