In the circle given below, let OA = 1 unit, OB = 13 unit and PQ ⊥ OB. Then, the area of the triangle PQB (in square units) is :
Mathematicscircle2021medium
Let A(1, 4) and B(1, −5) be two points. Let P be a point on the circle
(x − 1)2 + (y − 1)2 = 1 such that (PA)2 + (PB)2 have maximum value, then the points, P, A and B lie on :
Mathematicscircle2021medium
If the locus of the mid-point of the line segment from the point (3, 2) to a point on the circle, x2 + y2 = 1 is a circle of radius r, then r is equal to :
Mathematicscircle2021hard
Let the lengths of intercepts on x-axis and y-axis made by the circle
x2 + y2 + ax + 2ay + c = 0, (a < 0) be 22 and 25, respectively. Then the shortest distance from origin to a tangent to this circle which is perpendicular to the line x + 2y = 0, is equal to :
Mathematicscircle2021medium
The line 2x − y + 1 = 0 is a tangent to the circle at the point (2, 5) and the centre of the circle lies on x − 2y = 4. Then, the radius of the circle is :
Mathematicscircle2021medium
Choose the incorrect statement about the two circles whose equations are given below :
x2 + y2 − 10x − 10y + 41 = 0 and
x2 + y2 − 16x − 10y + 80 = 0
Mathematicscircle2021medium
Let the tangent to the circle x2 + y2 = 25 at the point R(3, 4) meet x-axis and y-axis at points P and Q, respectively. If r is the radius of the circle passing through the origin O and having centre at the incentre of the triangle OPQ, then r2 is equal to :
Mathematicscircle2021medium
Two tangents are drawn from a point P to the circle x2 + y2 − 2x − 4y + 4 = 0, such that the angle between these tangents is {\tan ^{ - 1}}\left( {{{12} \over 5}} \right), where {\tan ^{ - 1}}\left( {{{12} \over 5}} \right)∈(0, π). If the centre of the circle is denoted by C and these tangents touch the circle at points A and B, then the ratio of the areas of ΔPAB and ΔCAB is :
Mathematicscircle2021medium
Choose the correct statement about two circles whose equations are given below :
x2 + y2 − 10x − 10y + 41 = 0
x2 + y2 − 22x − 10y + 137 = 0
Mathematicscircle2021easy
For the four circles M, N, O and P, following four equations are given :
Circle M : x2 + y2 = 1
Circle N : x2 + y2 − 2x = 0
Circle O : x2 + y2 − 2x − 2y + 1 = 0
Circle P : x2 + y2 − 2y = 0
If the centre of circle M is joined with centre of the circle N, further center of circle N is joined with centre of the circle O, centre of circle O is joined with the centre of circle P and lastly, centre of circle P is joined with centre of circle M, then these lines form the sides of a :
Mathematicscircle2021medium
Let S1 : x2 + y2 = 9 and S2 : (x − 2)2 + y2 = 1. Then the locus of center of a variable circle S which touches S1 internally and S2 externally always passes through the points :
Mathematicscircle2021medium
Let r1 and r2 be the radii of the largest and smallest circles, respectively, which pass through the point (−4, 1) and having their centres on the circumference of the circle x2 + y2 + 2x + 4y − 4 = 0. If {{{r_1}} \over {{r_2}}} = a + b\sqrt 2, then a + b is equal to :
Mathematicscircle2021medium
Let the circle S : 36x2 + 36y2 − 108x + 120y + C = 0 be such that it neither intersects nor touches the co-ordinate axes. If the point of intersection of the lines, x − 2y = 4 and 2x − y = 5 lies inside the circle S, then :
Mathematicscircle2021medium
Consider a circle C which touches the y-axis at (0, 6) and cuts off an intercept 65 on the x-axis. Then the radius of the circle C is equal to :
Mathematicscircle2021hard
Two tangents are drawn from the point P(−1, 1) to the circle x2 + y2 − 2x − 6y + 6 = 0. If these tangents touch the circle at points A and B, and if D is a point on the circle such that length of the segments AB and AD are equal, then the area of the triangle ABD is equal to :
Mathematicscircle2021medium
Let P and Q be two distinct points on a circle which has center at C(2, 3) and which passes through origin O. If OC is perpendicular to both the line segments CP and CQ, then the set {P, Q} is equal to :
Mathematicscircle2021medium
Let A={(x,y)∈R×R∣2x2+2y2−2x−2y=1}, B={(x,y)∈R×R∣4x2+4y2−16y+7=0} and C={(x,y)∈R×R∣x2+y2−4x−2y+5≤r2}.
Then the minimum value of |r| such that A∪B⊆C is equal to
Mathematicscircle2021hard
If a line along a chord of the circle 4x2 + 4y2 + 120x + 675 = 0, passes through the point (−30, 0) and is tangent to the parabola y2 = 30x, then the length of this chord is :
Mathematicscircle2021medium
A circle C touches the line x = 2y at the point (2, 1) and intersects the circle
C1 : x2 + y2 + 2y − 5 = 0 at two points P and Q such that PQ is a diameter of C1. Then the diameter of C is :
Mathematicscircle2021medium
Let Z be the set of all integers,
A={(x,y)∈Z×Z:(x−2)2+y2≤4}B={(x,y)∈Z×Z:x2+y2≤4}C={(x,y)∈Z×Z:(x−2)2+(y−2)2≤4}
If the total number of relation from A ∩ B to A ∩ C is 2p, then the value of p is :