Circles Questions (554)

If Q, S are two points on the circle \(x^2 + y^2 = 4\) such that the tangents QP, SR are parallel. If PS, QR intersect at T then \(\left(\dfrac{QT}{PQ}\right)^2 + \left(\dfrac{ST}{RS}\right)^2 + PQ \cdot RS \neq\)
Circle touches the x-axis at (3, 0) and making an intercept of length 8 on the y-axis. The equation of the circle is:
The equation of the circle described on the chord \(3x + y + 5 = 0\) of the circle \(x^2 + y^2 = 16\) as diameter is
The least and the greatest distances of the point (10, 7) from the circle \(x^2 + y^2 - 4x - 2y - 20 = 0\) are
The centre of a circle passing through the points (0, 0), (1, 0) and touching the circle \(x^2 + y^2 = 9\) is
How many ordered pair of integers \((a, b)\) satisfy all the following inequalities: \(a^2 + b^2
A circle $S$ whose radius is $1$ unit, touches the X-axis at point $A$. The centre $O$ of $S$ lies in the first quadrant. The tangent from the origin $O$ to the circle touches it at $T$ and a point $P$ lies on it such that the triangle $OAP$ is a right-angled triangle at $A$ and its perimeter is $8$ unit. The length of $QP$ is ___.
If a circle touches the hypotenuse of a right-angled triangle at its middle point and passes through the middle point of shorter side. If $a$ and $b$ $(a < b)$ be the length of the sides and the radius of the circle is $\frac{b}{ka}\sqrt{a^2 + b^2}$, then the value of $k$ is __________.
Two circles are given by \[x^2 + y^2 - 8 = 0\] and \[(x - a)^2 + y^2 - 8 = 0\]. The common chord is obtained by subtracting the equations: \[2ax - a^2 = 0\], which gives \[x = \frac{a}{2}\]. If the common chord subtends a right angle at the origin, find the value of a.
For any \(\lambda \in \mathbb{R}\), the locus of \(x^2 + y^2 - 2\lambda x - 2\lambda y + \lambda^2 = 0\) touches the line
The circles \(x^2 + y^2 + 2ax + 2ny = 0\) and \(x^2 + y^2 + 2bx + 2ny = 0\) touch each other if
Consider the circles \(C_1 \equiv x^2 + y^2 - 2x - 4y - 4 = 0\) and \(C_2 \equiv x^2 + y^2 + 2x + 4y + 4 = 0\) and the line \(L \equiv x + 2y + 2 = 0\), then
The tangent to the circle \(C_1 : x^2 + y^2 - 2x - 1 = 0\) at the point \((2, 1)\) cuts off a chord of length 4 from a circle \(C_2\) whose centre is \((3, -2)\). The radius of \(C_2\) is
The given circle equation is \(x^2 + y^2 + 2x - 4y - 4 = 0\). The centre of the given circle is (–1, 2) and its radius is 3. Find the centre of the required circle.
The equation of a circle which touches the line \(2x - y = 1\) at (1, 1) and also touches the line \(2x + y = 4\) is
On the side $AC$ of an acute angled triangle $ABC$ a point $D$ is taken, such that $AD = 1, DC = 2$ and $BD$ is an altitude of $\triangle ABC$. A circle of radius $2$, which passes through points $A$ and $D$ and touches a circle at the point $D$ circumscribed about the $\triangle BDC$. If the area of $\triangle ABC$ is $A$ then the value of $\frac{1}{11}[A]$ is equal to __________. (Where $[.]$ represents G.I.F)
The circle passing through the intersection of the circles, $x^2 + y^2 - 6x = 0$ and $x^2 + y^2 - 4y = 0$, having its centre on the line, $2x - 3y + 12 = 0$, also passes through the point
The straight line \(y = mx + c\) cuts the circle \(x^2 + y^2 = a^2\) in real points if \(a\sqrt{1 + m^2} > |c|\).State whether the statement is true or false.
The tangent from point P(4, 7) is drawn to a circle with centre O(0, 0). If C is the point of contact of the tangent, find PA · PB where A and B are the ends of the chord through P.Given: PA · PB = (PC)², and the centre of the circle is O(0,0). Find PA · PB.
Let point P(x1, y1) be any point on the circle (x1 - 3)2 + (y1 + 2)2 = 5r2. Find the area between two circles if the length of tangent drawn from point P(x1, y1) to the circle (x - 3)2 + (y + 2)2 = r2 is such that the area is kπ.
We have two straight lines \(x - y = 1\) and \(2x + y = 3\). The tangent to the circle at point \(P(1, -1)\) (where the two lines intersect) with centre \(C\left(\dfrac{4}{3}, \dfrac{1}{3}\right)\) is:
If a circle passes through the point \((a, b)\) and cuts the circle \(x^2 + y^2 = 4\) orthogonally, then the locus of its centre is
If a circle of radius 2 unit touches the \(y\)-axis at the origin, \('O'\) and intersects the lines \(y = (2-\sqrt{3})x\) and \(y = -(2+\sqrt{3})x\) in the I and IV quadrants at \(A\) and \(B\) respectively, then area of \(\triangle AOB\) (in square units) is:
The number of possible integral values of $m$ for which the circle $x^2 + y^2 = 4$ and $x^2 + y^2 - 6x - 8y + m^2 = 0$ have exactly two common tangents is __________.
If a circle passes through the point \((a, b)\) and cuts the circle \(x^2 + y^2 = k^2\) orthogonally, the equation of the locus of its centre is
The tangent and the normal lines at the point \((\sqrt{3}, 1)\) to the circle x2 + y2 = 4 and the X-axis form a triangle. The area of this triangle (in square units) is
If the line x + 2by + 7 = 0 is a diameter of the circle x2 + y2 - 6x + 2y = 0, then b =
A circle with radius 1 has diameter AB. C lies on this circle such that \(\frac{\widehat{A C}}{\widehat{B C}}\) = 4. \(\overline{A C}\) divides the circle into two parts, and we will label the smaller part Region I. Similarly, \(\overline{B C}\) also divides the circle into two parts, and we will denote the smaller one as Region II. The difference between the areas of Region I and II is : (where \(\widehat{A C}\) represents are AC, \(\overline{A C}\) represents chord AC)
Find the number of ordered pairs (a, b) that satisfy all three circle inequalities with centers at (1,1), (1,2), and (2,1).
29. If a chord of the circle \(x^2 + y^2 - 4x - 2y - c = 0\) is trisected at the points \((1/3, 1/3)\) and \((8/3, 8/3)\), then the radius of the circle will be:
The circle S touches the sides AB and AD of the rectangle ABCD and cuts the side DC at a single point F and the side BC at a single point E. If \(|AB| = 32\), \(|AD| = 40\) and \(|BE| = 1\). The angle between pair of tangents drawn from the point D to the circle S is:
Circle(s) touching x-axis at a distance 3 from the origin and having an intercept of length \(2\sqrt{7}\) on y-axis is(are):
A point P moves such that the sum of the squares of its distances from the sides of a given square is a constant. Then point P moves on
Let A and B are two points both lying within a given circle S, and P be a point on circumference of S at which AB subtends the greatest angle.Statement-1: If \(A \equiv (1, 1)\), \(B \equiv (1, -1)\) and equation of S is \(x^2 + y^2 = 4\) then P will be \((2, 0)\)Statement-2: P will be the point where a circle passing through A and B touches the circle S.
Let ABCD be a square of side length 2 units. \(C_2\) is the circle through vertices A, B, C, D and \(C_1\) is the circle touching all the sides of the square ABCD. L is a line through A.If P is a point on \(C_1\) and Q is another point on \(C_2\), then \(\frac{PA^2 + PB^2 + PC^2 + PD^2}{QA^2 + QB^2 + QC^2 + QD^2}\) is equal to:
If the tangent to the conic, \(y - 6 = x^2\) at (2, 10) touches the circle, \(x^2 + y^2 + 8x - 2y = k\) (for some fixed \(k\)) at a point \((\alpha, \beta)\), then \((\alpha, \beta)\) is
The circle passing through \((1, -2)\) and touching the axis of x at \((3, 0)\) also passes through the point:
Find the locus of the middle points of chords of a given circle \(x^2 + y^2 = a^2\) which subtend a right angle at the fixed point \((p, q)\).
An altitude BD and a bisector BE are drawn in the triangle ABC from the vertex B. It is known that the length of side AC = 1, and the magnitudes of the angles \(\angle BEC\), \(\angle ABD\), \(\angle ABE\), \(\angle BAC\) form an arithmetic progression. The area of circle circumscribing \(\triangle ABC\) is:
The locus of the centres of the circles, which touch the circle, \(x^2 + y^2 = 1\) externally, also touch the y-axis and lie in the first quadrant, is:
Consider 3 equal circles of radius \(r_1\) within a circle of radius \(r_2\) each to touch the other two and the given circle.Statement-1: \(\frac{r_1}{r_2} = \frac{\sqrt{3}}{\sqrt{3}+1}\)Statement-2: Incentre of triangle formed by joining centres of 3 equal circles is same as centre of given circle.
If the circle \(C_1: x^2 + y^2 = 16\) intersects another circle \(C_2\) of radius 5 in such a manner that the common chord is of maximum length and has a slope equal to \(\frac{3}{4}\), then the coordinates of the centre of \(C_2\) are:
The circle passing through \((1, -2)\) and touching the axis of x at \((3, 0)\) also passes through the point:
Given a line segment AB, A ≡ (0, 0) and B(a, 0). Three circles S₁, S₂, S₃ of radius R are centred at the end points and the midpoint of the line segment AB. A fourth circle S₄ is drawn touching the 3 given circles. If 0
In an acute triangle ABC, point H is the intersection point of altitude CE to AB and altitude BD to AC. A circle with DE as its diameter intersects AB and AC at points F and G respectively. If BC = 25, BD = 20 and BE = 7. Let FG and AH intersect at point K, then the length of AK is:
Let A = (0,0), B = (4,0) and on segment AB is given a point M. On the same side of AB, squares AMCD and BMFE are constructed above AB. The circumcircles S₁ and S₂ of two squares AMCD and BMFE respectively have centres P and Q, and intersect in M and another point N.The point of intersection of the lines FA and BC is:
A circle \(C\) passes through the points of intersection of the parabola \(y + 1 = (x - 4)^2\) and the \(x\)-axis. The length of tangent from origin to \(C\) is:
Let the bisector of ∠A of △ABC meets BC in D and the circumcircle of △ABC in E. Analyze: AD is less than the G.M. (Geometric Mean) of AB and AC.
If S₁, S₂ and S₃ are three circles congruent to C₂ and touch both C₁ and C₂; then the area of triangle formed by joining centres of the circles S₁, S₂ and S₃ is (in square units)
Let A = (0, 0), B = (4, 0) and on segment AB is given a point M. On the same side of AB, squares AMCD and BMFE are constructed above AB. The circumcircles S₁ and S₂ of two squares AMCD and BMFE respectively have centres P and Q, and intersect in M and another point N.For all positions of M varying along the segment AB, the line MN passes through the fixed point R(a, b), then a + b = ?