Question

If (2, 4) is a point interior to the circle $${x^2} + {y^2} - 6x - 10y + \lambda = 0$$      and the circle does not cut the axes at any point then $$\lambda $$ belongs to the interval :

A. $$\left( {25,\,32} \right)$$  
B. $$\left( {9,\,32} \right)$$
C. $$\left( {32,\, + \infty } \right)$$
D. none of these
Answer :   $$\left( {25,\,32} \right)$$
Solution :
$$\eqalign{ & {2^2} + {4^2} - 6 \times 2 - 10 \times 4 + \lambda < 0 \cr & \Rightarrow \,\lambda - 32 < 0{\text{ or }}\lambda < 32 \cr & {\text{Solving }}y = 0,\,{x^2} + {y^2} - 6x - 10y + \lambda = 0, \cr & {\text{we get }}{x^2} - 6x + \lambda = 0, \cr & {\text{which must have imaginary roots i}}{\text{.e}}{\text{.,}} \cr & 36 - 4\lambda < 0{\text{ i}}{\text{.e}}{\text{., }}\lambda > 9 \cr & {\text{Solving }}x = 0,\,{x^2} + {y^2} - 6x - 10y + \lambda = 0, \cr & {\text{we get }}{y^2} - 10y + \lambda = 0, \cr & {\text{which must have imaginary roots i}}{\text{.e}}{\text{.,}} \cr & 100 - 4\lambda < 0{\text{ i}}{\text{.e}}{\text{., }}\lambda > 25.{\text{ So 25}} < \lambda < 32. \cr} $$

Releted MCQ Question on
Geometry >> Circle

Releted Question 1

A square is inscribed in the circle $${x^2} + {y^2} - 2x + 4y + 3 = 0.$$      Its sides are parallel to the coordinate axes. The one vertex of the square is-

A. $$\left( {1 + \sqrt 2 ,\, - 2 } \right)$$
B. $$\left( {1 - \sqrt 2 ,\, - 2 } \right)$$
C. $$\left( {1 - 2 ,\, + \sqrt 2 } \right)$$
D. none of these
Releted Question 2

Two circles $${x^2} + {y^2} = 6$$    and $${x^2} + {y^2} - 6x + 8 = 0$$     are given. Then the equation of the circle through their points of intersection and the point $$\left( {1,\,1} \right)$$  is-

A. $${x^2} + {y^2} - 6x + 4 = 0$$
B. $${x^2} + {y^2} - 3x + 1 = 0$$
C. $${x^2} + {y^2} - 4y + 2 = 0$$
D. none of these
Releted Question 3

The centre of the circle passing through the point (0, 1) and touching the curve $$y = {x^2}$$   at $$\left( {2,\,4} \right)$$  is-

A. $$\left( {\frac{{ - 16}}{5},\,\frac{{27}}{{10}}} \right)$$
B. $$\left( {\frac{{ - 16}}{7},\,\frac{{53}}{{10}}} \right)$$
C. $$\left( {\frac{{ - 16}}{5},\,\frac{{53}}{{10}}} \right)$$
D. none of these
Releted Question 4

The equation of the circle passing through $$\left( {1,\,1} \right)$$  and the points of intersection of $${x^2} + {y^2} + 13x - 3y = 0$$      and $$2{x^2} + 2{y^2} + 4x - 7y - 25 = 0$$      is-

A. $$4{x^2} + 4{y^2} - 30x - 10y - 25 = 0$$
B. $$4{x^2} + 4{y^2} + 30x - 13y - 25 = 0$$
C. $$4{x^2} + 4{y^2} - 17x - 10y + 25 = 0$$
D. none of these

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Circle


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