Home
Class 12
MATHS
The locus of the point (l, m) so that lx...

The locus of the point `(l, m)` so that `lx+my=1` touches the circle `x^(2)+y^(2)=a^(2)` is :a)`x^(2)+y^(2)-ax=0` b)`x^(2)+y^(2)=1/a^(2)` c)`y^(2)=4ax` d)`x^(2)+y^(2)-ax-ay+a^(2)=0`

A

`x^(2)+y^(2)-ax=0`

B

`x^(2)+y^(2)=1/a^(2)`

C

`y^(2)=4ax`

D

`x^(2)+y^(2)-ax-ay+a^(2)=0`

Text Solution

Verified by Experts

The correct Answer is:
B
Promotional Banner

Similar Questions

Explore conceptually related problems

The circles x^(2)+y^(2)-4x-6y-12=0 and x^(2)+y^(2)+4x+6y+4=0

The locus of a point which moves so that the ratio of the length of the tangents to the circles x^(2)+ y^(2)+ 4x+3 =0 and x^(2)+ y^(2) -6x +5=0 is 2 : 3 is a) 5x^(2) +5y^(2) - 60x +7=0 b) 5x^(2) +5y^(2) +60x -7=0 c) 5x^(2) +5y^(2) -60x -7=0 d) 5x^(2) +5y^(2) +60x +7=0

ABCD is a square with side a. If AB and AD are along the coordinate axes, then the equation of the circle passing through the vertices A, B and D is a) x^(2)+y^(2)=sqrt(2a)(x+y) b) x^(2)+y^(2)=a/(sqrt(2))(x+y) c) x^(2)+y^(2)=a(x+y) d) x^(2)+y^(2)=a^(2)(x+y)

The equation of the sphere whose centre is (6, -1, 2) and which touches the plane 2x-y+2z-2=0 , is :a) x^(2)+y^(2)+z^(2)-12x+12y-4z-16=0 b) x^(2)+y^(2)+z^(2)-12x+2y-4z=0 c) x^(2)+y^(2)+z^(2)-12x+2y-4z+16=0 d) x^(2)+y^(2)+z^(2)-12x+2y-4z+6=0

If xe^(xy) + ye^(-xy) = sin ^(2) x , then (dy)/(dx) at x =0 is a) 2y^(2) -1 b) 2y c) y^(2) -y d) y^(2) -1

The shortest distance between the circles (x-1) ^(2) + (y +2) ^(2) =1 and (x + 2) ^(2)+ (y-2) ^(2) = 4 is a)1 b)2 c)3 d)4