Geometric properties of second-order curves and their canonical equations
[65/89%]Find the radius and the coordinates of the center of the circle:
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Under what necessary and sufficient condition does the equation define a circle? Express the radius and the coordinates of the center of the circle in terms of the coefficients of the equation.
Find the equation of the circle with center at the point , tangent to the line .
Find the necessary and sufficient condition for the line :
to have no common points with the circle
to have two common points with this circle
to be tangent to this circle.
Find the equation of the tangent line drawn to the circle at the point .
Find the equations of the tangent lines to the circle passing through the point .
Find the equations of the tangent lines to the circle , parallel to the line .
Verify that the two given circles are tangent to each other, and find the equation of their common tangent line passing through the point of tangency:
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Find the equations of the common tangent lines to the circles and .
Through a point lying outside a circle, a line tangent to the circle at a point is drawn, and another line intersecting the circle at points and . Prove that
Two circles are externally tangent. Through their point of tangency a line is drawn, meeting the first circle at one more point and the second circle at one more point . Prove that the tangent lines to the circles at the points and are parallel.
Prove that the set of points such that, for two fixed points and , the ratio is constant and equal to , is a straight line when and a circle when . Express the radius of this circle in terms of and the length of the segment .
Prove that the set of points such that, for two fixed points and , the sum is constant and equal to , is an ellipse with foci and . Express the lengths of the semi-axes of this ellipse in terms of and the length of the segment .
Prove that the set of points such that, for two fixed points and , the absolute value of the difference is constant and equal to , is a hyperbola with foci and . Express the semi-axes of this hyperbola in terms of and the length of the segment .
Prove that the set of points equidistant from a fixed point and a fixed line is a parabola with focus and directrix .
Determine the sets of points which, in a rectangular coordinate system, are given by the inequalities:
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What curves in the plane are given by the following parametric equations:
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Prove that the parametric equations define an ellipse with center at the point and with semi-axes and .
Prove that the parametric equations , where , define the right branch of a hyperbola with center at the point and with semi-axes and . How should these equations be modified to define both branches of the hyperbola?
Sketch the set of points which, in polar coordinates, is given by the equation:
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In the plane a segment is given. Find the set of points such that the angle at the vertex in the triangle is twice the angle at the vertex .
A point lies outside an ellipse with foci , the segments meet the ellipse at points respectively, and is the point of intersection of the segments . Prove that a circle can be inscribed in the quadrilateral .
Find the lengths of the semi-axes, the eccentricity, the coordinates of the foci, and find the equations of the directrices of the ellipse:
Given the ellipse . Determine whether the point lies on the ellipse, inside it, or outside it:
Compute the length of the focal chord of the ellipse , perpendicular to the major axis.
In a given coordinate system an ellipse has a canonical equation. Find this equation, if:
the distance between the vertices lying on the major axis equals 16, and the distance between the foci equals 10
the chord joining two vertices of the ellipse has length 5 and is inclined to its major axis at an angle
the foci of the ellipse are the points , and the point belongs to the ellipse
the foci of the ellipse are the points , and the directrices are the lines
the distance from a directrix to the nearest vertex equals 4, and to the vertex lying on the axis equals 8
the triangle with vertices at the foci and at the end of the minor axis is equilateral, and the diameter of the circle passing through the center and two vertices of the ellipse equals 7
the segment of the axis between the focus and the far vertex of the major axis is bisected by the second focus , and the distance from to the line passing through and the vertex of the minor axis equals
the directrices of the ellipse are the lines , and the quadrilateral with vertices at the foci and the ends of the minor axis is a square
the eccentricity of the ellipse equals , and the quadrilateral whose vertices are the vertices of the ellipse is circumscribed about a circle of radius 4.8.
Compute the eccentricity of the ellipse, if:
the distance between the foci equals the arithmetic mean of the lengths of the axes
the segment between a focus and the far vertex of the major axis is divided by the second focus in the ratio
the distance from a focus to the far vertex of the major axis is 1.5 times the distance to the vertex of the minor axis
the segment between the foci is seen from the end of the minor axis at a right angle
the major axis is seen from the end of the minor axis at an angle of
the segment between a focus and the far vertex of the major axis is seen from the end of the minor axis at a right angle
the sides of a square inscribed in the ellipse pass through the foci of the ellipse.
Find the equations of the sides of a square inscribed in the ellipse . What fraction of the area bounded by the ellipse is the area of this square?
Find the set of points that are the midpoints of chords of the ellipse parallel to the line .
Through the point draw a chord of the ellipse that is bisected at this point.
Through the point draw a line meeting the ellipse at two points and such that .
On the ellipse find the points from which the segment joining the foci is seen:
at a right angle
at an angle of
at the largest angle.
Find the equations of the families of ellipses:
with common foci
with common directrices and common center at the origin.
Find the equation of an ellipse, if:
the points and are the foci, and the line is one of the directrices
the point is one of the foci, the point is an endpoint of the major axis, and the eccentricity equals
the axes of the ellipse are parallel to the coordinate axes, the points and belong to the ellipse, and the point is at distance from one of the foci and at distance 6 from the corresponding directrix.
Let be the center of an ellipse, its semi-axes, and and points of the ellipse such that the lines and are mutually perpendicular.
Prove that the quantity is constant for all possible pairs of points and .
Find the largest and smallest values of the length of the segment .
Find the semi-axes, the eccentricity, the coordinates of the foci, and find the equations of the directrices and asymptotes of the hyperbola:
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Given the hyperbola . Determine whether the point lies on the hyperbola, inside one of its branches, or between the branches:
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Compute the length of the focal chord of the hyperbola , perpendicular to the real axis.
In a given coordinate system a hyperbola has a canonical equation. Find this equation, if:
the distance between the vertices equals 10, and the distance between the foci equals 12
the length of the real axis equals 1, and the point belongs to the hyperbola
the directrices of the hyperbola are the lines , and the point belongs to the hyperbola
the length of the imaginary semi-axis equals 1, and a vertex of the hyperbola divides the segment between the foci in the ratio
the eccentricity of the hyperbola equals , and the distance from a vertex to the nearest focus equals 2
the point , belonging to the hyperbola, is at distance from the left focus
the angle between the asymptotes containing a focus equals , and the distance from a directrix to the nearest vertex equals
the point belongs to the hyperbola, and the asymptotes are the lines
the point belongs to the hyperbola, and the asymptotes are the lines .
Find the canonical equation of the hyperbola containing the point and having asymptotes (compare with problem ).
Compute the eccentricity of the hyperbola, if:
its semi-axes are equal (an equilateral hyperbola)
the angle between the asymptotes containing a focus equals
the asymptotes of the hyperbola are the lines .
Compute the eccentricity of the hyperbola having, in a given coordinate system, a canonical equation, if:
the distances from the point , belonging to the hyperbola, to the directrices are in the ratio
the sum of the distances from the point to the asymptotes of the hyperbola equals 20 / 3.
Express the eccentricity of the hyperbola in terms of the eccentricity of an ellipse having, in common with this hyperbola, focal chords perpendicular to the real axis.
Find the equation of the hyperbola that has, in common with the ellipse , focal chords perpendicular to the real axis.
Find the set of points that are the midpoints of chords of the hyperbola parallel to the line .
Through the point draw a chord of the hyperbola that is bisected at this point.
On the hyperbola find the points from which the segment joining the foci is seen:
at a right angle
at an angle of
at the largest angle.
Find the equations of the families of hyperbolas:
with common foci
with common directrices and common center at the origin
with common asymptotes .
Find the equation of a hyperbola, if:
the points and are the foci, and the line is one of the directrices
the point is one of the foci, the point is a vertex, and the eccentricity equals
the point is one of the foci, and the lines are the asymptotes.
Prove that for a given hyperbola the following quantities are constant, and express them in terms of the semi-axes of the hyperbola:
the product of the distances from any point of the hyperbola to its asymptotes
the area of a parallelogram, one of whose vertices lies on the hyperbola and two of whose sides lie on the asymptotes.
Prove that the vertices of the hyperbola and the four points of intersection of its directrices with its asymptotes lie on one circle. Express the radius of this circle in terms of the length of the real semi-axis.
Find the coordinates of the focus and find the equation of the directrix of the parabola:
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How are the following points located with respect to the parabola :
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Compute the length of the focal chord of the parabola , perpendicular to the axis of the parabola.
In a given coordinate system a parabola has a canonical equation. Find this equation, if:
the point belongs to the parabola
the distance from the focus to the directrix equals 12
the length of the chord passing through the focus at an angle of to the axis of the parabola equals 18.
Find the equation of the set of points that are the midpoints of chords of the parabola parallel to the line .
Prove that the midpoints of chords of a parabola parallel to a given line lie on a line parallel to the axis of the parabola.
Through the point draw a chord of the parabola that is bisected at this point.
On the parabola find a point such that:
the line passing through the point and the focus of the parabola makes an angle of with the axis
the area of the triangle with vertices at the required point , the focus of the parabola, and the point where the axis of the parabola meets the directrix equals 5
the distance from the point to the vertex of the parabola equals the distance from to the focus
the distances from the point to the vertex of the parabola and to the focus of the parabola are in the ratio .
Find the set of values that can be taken by the ratio of the distance from a point of the parabola to its vertex to the distance from the same point to the focus.
Find the equation of the parabola with parameter , whose vertex has coordinates , and whose axis has the direction coinciding:
with the positive direction of the axis
with the negative direction of the axis
with the positive direction of the axis
with the negative direction of the axis .
Find the equations of the family of parabolas:
having common focus and symmetric with respect to the axis
having common directrix and symmetric with respect to the axis .
Find the equation of a parabola, if:
the point is the focus, and the line is the directrix
the point is the focus, and the line is the directrix
the point is the focus, the parabola is symmetric with respect to the axis , and is tangent to the axis
the axis of the parabola is parallel to the axis , the focus lies on the axis , the parabola passes through the origin and cuts off on the axis a segment of length 6.
Find the largest radius of a circle lying inside the parabola and tangent to this parabola at its vertex.
Two parabolas, whose axes are mutually perpendicular, have four points of intersection. Prove that these four points lie on one circle.
The curves and intersect at four points lying on one circle. Find the coordinates of the center of this circle.