# Ellipse Sentence Examples

It is the envelope of circles described on the central radii of an

**ellipse**as diameters.The tricky part is making an

**ellipse**at a point different from the origin.When the

**ellipse**becomes a circle, the meridian line becomes a straight line parallel to the axis, and the film passes into the form of a cylinder of revolution.The Greek geometers were perfectly familiar with the property of an

**ellipse**which in the Cartesian notation is x 2 /a 2 +y 2 /b 2 =1, the equation of the curve; but it was as one of a number of properties, and in no wise selected out of the others for the characteristic property of the curve.The nature of the two kinds of branches is best understood by considering them as projections, in the same way as we in effect consider the hyperbola and the parabola as projections of the

**ellipse**.The angle cp is termed the eccentric angle, and is geometrically represented as the angle between the axis of x (the major axis of the

**ellipse**) and the radius of a point on the auxiliary circle which has the same abscissa as the point on the**ellipse**.When the

**ellipse**differs infinitely little from a circle, the equation of the meridian line becomes approximately y = a+c sin (x/a) where c is small.Arrow heads at the ends of an axis of an

**ellipse**indicate tension as distinct from compression, and the semi-axes in magnitude and direction represent the principal stresses.Above this entrance it widens into an

**ellipse**a mile long, half a mile broad and 15 ft.Newton replied promptly, "an

**ellipse**," and on being questioned by Halley as to the reason for his answer he replied, " Why, I have calculated it."AdvertisementSimilarly any other property might be used as a definition; an

**ellipse**is the locus of a point such that the sum of its distances from two fixed points (the foci) is constant, &c., &c.Thus the curve of the first order or right line consists of one branch; but in curves of the second order, or conics, the

**ellipse**and the parabola consist each of one branch, the hyperbola of two branches.As regards the so-called hyperbolisms, observe that (besides the single asymptote) we have in the case of those of the hyperbola two parallel asymptotes; in the case of those of the

**ellipse**the two parallel asymptotes become imaginary, that is, they disappear; and in the case of those of the parabola they become coincident, that is, there is here an ordinary asymptote, and a special asymptote answering to a cusp at infinity.Using a powerful and elaborate analysis, Adams ascertained that this cluster of meteors, which belongs to the solar system, traverses an elongated

**ellipse**in 334 years, and is subject to definite perturbations from the larger planets, Jupiter, Saturn and Uranus.This circle, projected in Q perspective as an

**ellipse**, is shown in X the figure.AdvertisementIf projected with this velocity in any direction the point of projection will be at the end of the minor axis of the orbit, because this is the only point of an

**ellipse**of which the distance from the focus is equal to the semi-major axis of the curve, and therefore the only point at which the distance of the body from the sun is equal to its mean distance.He long adhered to the traditional belief that all celestial revolutions must be performed equably in circles; but a laborious computation of seven recorded oppositions of Mars at last persuaded him that the planet travelled in an

**ellipse**, one focus of which was occupied by the sun.Bessel announced, in December 1838, the perspective yearly shifting of 61 Cygni in an

**ellipse**with a mean radius of about one-third of a second.The orbit of the moon around the earth, though not a fixed curve of any class, is elliptical in form, and may be represented by an

**ellipse**which is constantly changing its form and position, and has the earth in one of its foci.The relation of the

**ellipse**to the other conic sections is treated in the articles Conic Section and Geometry; in this article a summary of the properties of the curve will be given.AdvertisementIf the tangents be at right angles, then the locus of the point is a circle having the same centre as the

**ellipse**; this is named the director circle.The intersections of the lines drawn from corresponding points are points on the

**ellipse**.The thread is now stretched taut by a pencil, and the pencil moved; the curve traced out is the desired

**ellipse**.Let P be the intersection of the line SL with the line RAM, then it can be readily shown that P is a point on the

**ellipse**.Then with centre 0 1 and radius OJ, =OA 1, describe an arc. By reflecting the two arcs thus described over the centre the

**ellipse**is approximately described.AdvertisementIn ancient geometry the name was restricted to the three particular forms now designated the

**ellipse**, parabola and hyperbola, and this sense is still retained in general works.One definition, which is of especial value in the geometrical treatment of the conic sections (

**ellipse**, parabola and hyperbola) in piano, is that a conic is the locus of a point whose distances from a fixed point (termed the focus) and a fixed line (the directrix) are in constant ratio.This ratio, known as the eccentricity, determines the nature of the curve; if it be greater than unity, the conic is a hyperbola; if equal to unity, a parabola; and if less than unity, an

**ellipse**.A conic may also be regarded as the polar reciprocal of a circle for a point; if the point be without the circle the conic is an

**ellipse**, if on the circle a parabola, and if within the circle a hyperbola.An important property of confocal systems is that only two confocals can be drawn through a specified point, one being an

**ellipse**, the other a hyperbola, and they intersect orthogonally.The definitions given above reflect the intimate association of these curves, but it frequently happens that a particular conic is defined by some special property (as the

**ellipse**, which is the locus of a point such that the sum of its distances from two fixed points is constant); such definitions and other special properties are treated in the articles**Ellipse**, Hyperbola and Parabola.When the cutting plane is inclined to the base of the cone at an angle less than that made by the sides of the cone, the latus rectum is greater than the intercept on the ordinate, and we obtain the

**ellipse**; if the plane is inclined at an equal angle as the side, the latus rectum equals the intercept, and we obtain the parabola; if the inclination of the plane be greater than that of the side, we obtain the hyperbola.Pappus in his commentary on Apollonius states that these names were given in virtue of the above relations; but according to Eutocius the curves were named the parabola,

**ellipse**or hyperbola, according as the angle of the cone was equal to, less than, or greater than a right angle.His proofs are generally long and clumsy; this is accounted for in some measure by the absence of symbols and technical terms. Apollonius was ignorant of the directrix of a conic, and although he incidentally discovered the focus of an

**ellipse**and hyperbola, he does not mention the focus of a parabola.He also considered the two branches of a hyperbola, calling the second branch the "opposite" hyperbola, and shows the relation which existed between many metrical properties of the

**ellipse**and hyperbola.We may also notice Kepler's approximate value for the circumference of an

**ellipse**(if the semi-axes be a and b, the approximate circumference is ir(a+b)).The major axis of the

**ellipse**will be along the East-West line and the minor axis of the**ellipse**will be along the East-West line and the minor axis will be North-South.The mean is trimmed since some incorrect

**ellipse**fits produce extremely deviant parameter estimates that have a large influence on the mean.Using the

**ellipse**Tool, create a circular**ellipse**roughly 20 pixels in diameter on the left edge of the stage.The shadow on the Earth's surface was a very elongated

**ellipse**in these places.The tendrils are moderately thin and long; one made a narrow

**ellipse**in 5 hrs.The smaller

**ellipse**include the position of thin disk stars, the larger one that of thick disk stars.This quantity is equal to the width of the error

**ellipse**orthogonal to the visibility vector.Therefore, all that is needed to produce a sensitive refractive index sensor is a sensitive measure of the rotation of the polarization

**ellipse**.Principal strains, strain ellipsoid and strain

**ellipse**; special types of strain ellipsoid and Flinn plots.Thus it has a real centre, two foci, two directrices and two vertices; the transverse axis, joining the vertices, corresponds to the major axis of the

**ellipse**, and the line through the centre and perpendicular to this axis is called the conjugate axis, and corresponds to the minor axis of the**ellipse**; about these axes the curve is symmetrical.If the law of attraction is that of gravitation, the orbit is a conic section -

**ellipse**, parabola or hyperbola - having the centre of attraction in one of its foci; and the motion takes place in accordance with Kepler's laws (see Astronomy).But unless the orbit is an

**ellipse**the body will never complete a revolution, but will recede indefinitely from the centre of motion.Nevertheless, it should be observed that our globes take no account of the oblateness of our sphere; but as the difference in length between the circumference of the equator and the perimeter of a meridian

**ellipse**only amounts to o 16%, it could be shown only on a globe of unusual size.The major axis of any such aberrational

**ellipse**is always parallel to AC, i.e.As the

**ellipse**degenerates into the straight line joining its foci, the contracted parts of the unduloid become narrower, till at last the figure becomes a series of spheres in contact.About 3 metres in front of them was arranged a pair of smaller horizontal j aeroplanes, shaped like a long narrow

**ellipse**, which formed the rudder that effected changes of elevation, the driver being able by means of a lever to incline them up or down according as he desired to ascend or descend.The eccentricity of the

**ellipse**is in the general average about 0.055, whence the moon is commonly more than i' further from the earth at apogee than at perigee.Menaechmus discussed three species of cones (distinguished by the magnitude of the vertical angle as obtuse-angled, right-angled and acuteangled), and the only section he treated was that made by a plane perpendicular to a generator of the cone; according to the species of the cone, he obtained the curves now known as the hyperbola, parabola and

**ellipse**.In his extant Conoids and Spheroids he defines a conoid to be the solid formed by the revolution of the parabola and hyperbola about its axis, and a spheroid to be formed similarly from the

**ellipse**; these solids he discussed with great acumen, and effected their cubature by his famous "method of exhaustions."In that year, President Calvin Coolidge's wife, Grace Coolidge, allowed the D.C. public school district to put up a tree on the

**Ellipse**, near the Washington Monument.While the National tree was originally a cut tree, it is now a permanent, living fixture on the

**Ellipse**.While resembling the parabola in extending to infinity, the curve has closest affinities to the

**ellipse**.The passage of the maximum turgidity round the stem may vary in rapidity in different places, causing the circle to be replaced by an

**ellipse**.The varying direction of the inclining couple Pc may be realized by swinging the weight P from a crane on the ship, in a circle of radius c. But if the weight P was lowered on the ship from a crane on shore, the vessel would sink bodily a distance P/wA if P was deposited over F; but deposited anywhere else, say over Q on the water-line area, the ship would turn about a line the antipolar of Q with respect to the confocal

**ellipse**, parallel to FF', at a distance FK from F FK= (k2-hV/A)/FQ sin QFF' (2) through an angle 0 or a slope of one in m, given by P sin B= m wA FK - W'Ak 2V hV FQ sin QFF', (3) where k denotes the radius of gyration about FF' of the water-line area.The ratio of the axes of the

**ellipse**is sec a, the longer axis being in the plane of 0.Its earliest form is a rough

**ellipse**transfixed by an upright line, cp. In various Semitic alphabets this has been altered out of recognition, apparently from the writing of the symbol in cursive handwriting without lifting the pen.When the conic is an

**ellipse**the meridian line is in the form of a series of waves, and the film itself has a series of alternate swellings and contractions as represented in figs.In all these cases the internal pressure exceeds the external by 2T/a where a is the semi-transverse axis of the conic. The resultant of the internal pressure and the surface-tension is equivalent to a tension along the axis, and the numerical value of this tension is equal to the force due to the action of this pressure on a circle whose diameter is equal to the conjugate axis of the

**ellipse**.The evolute of this

**ellipse**is the caustic required.The

**ellipse**is therefore the only closed orbit.From this or otherwise it is readily deduced that the ordinates of an

**ellipse**and of the circle described on the major axis are in the ratio of the minor to the major axis.The area of the

**ellipse**is 7rab, where a, b are the semi-axes; this result may be deduced by regarding the**ellipse**as the orthogonal projection of a circle, or by means of the calculus.An

**ellipse**can generally be described to satisfy any five conditions.If now the strip be moved so that the point a is always on the minor axis, and the point b on the major axis, the point P describes the

**ellipse**.This shows that the C.P. is the antipole of the line of intersection of its plane with the free surface with respect to the momental

**ellipse**at the C.G.The star thus appears to describe a small

**ellipse**in the sky, and the nearer the star, the larger will this**ellipse**appear.Representing by P this position, it follows that the area of that portion of the

**ellipse**contained between the radii vectores FB and FP will bear the same ratio to the whole area of the**ellipse**that t does to T, the time of revolution.The general relations between the parabola,

**ellipse**and hyperbola are treated in the articles Geometry, Analytical, and Conic Sections; and various projective properties are demonstrated in the article Geometry, Projective.Elliptic orbits, and a parabolic orbit considered as the special case when the eccentricity of the

**ellipse**is 1, are almost the only ones the astronomer has to consider, and our attention will therefore be confined to them in the present article.From the properties of the

**ellipse**, A is the pericentre or nearest point of the orbit to the centre of attraction and B the apocentre or most distant point.Thus the core of a circle or an

**ellipse**is a concentric circle or**ellipse**of one quarter the size.Hence the area of an

**ellipse**whose axes are 2a and 2b is Trab; and the volume of an ellipsoid whose axes are 2a, 2b and 2c is t rabc. The area of a strip of an**ellipse**between two lines parallel to an axis, or the volume of the portion (frustum) of an ellipsoid between two planes parallel to a principal section, may be found in the same way.If the two forks have the same frequency, it is easily seen that the figure will be an

**ellipse**(including as limiting cases, depending on relative amplitude and phase, a circle and a straight line).It imitates the motions made in polishing a speculum by hand by giving both a rectilinear and a lateral motion to the polisher, while the speculum revolves slowly; by shifting two eccentric pins the course of the polisher can be varied at will from a straight line to an

**ellipse**of very small eccentricity, and a true parabolic figure can thus be obtained.If the pressure falls off uniformly, so that the pressure-curve is a straight line PDF sloping downwards and cutting AM in F, then the energy-curve will be a parabola curving downwards, and the velocity-curve can be represented by an

**ellipse**, or circle with centre F and radius FA; while the time-curve will be a sinusoid.It is clearly the form of the fundamental property (expressed in the terminology of the "application of areas") which led him to call the curves for the first time by the names parabola,

**ellipse**, hyperbola.Proposition 14 shows how to draw an

**ellipse**through five given points, and Prop. 15 gives a simple construction for the axes of an**ellipse**when a pair of conjugate diameters are given.The greatest displacement of the star from its mean position (the semi-axis major of the

**ellipse**) is called its parallax.Again, the locus of G is an arc of an

**ellipse**whose centre is in the intersection of the planes; since this arc is convex upwards the equilibrium is unstable.The pole 0 of the hodograph is inside on or outside the circle, according as the orbit is an

**ellipse**, parabola or hyperbola.In all the cases which have yet arisen in astronomy the extraneous forces are so small compared with the gravitation of the central body that the orbit is approximately an

**ellipse**, and the preliminary computations, as well as all determinations in which a high degree of precision is not necessary, are made on the hypothesis of elliptic orbits.If the rod is circular in section and perfectly uniform the end will describe a circle,

**ellipse**or straight line; but, as the elasticity is usually not exactly the same in all directions, the figure usually changes and revolves.He first brought the revolutions of our satellite within the domain of Kepler's laws, pointing out that her apparent irregularities could be completely accounted for by supposing her to move in an

**ellipse**with a variable eccentricity and directly rotatory major axis, of which the earth occupied one focus.Thus Whewell mistook Kepler's inference that Mars moves in an

**ellipse**for an induction, though it required the combination of Tycho's and Kepler's observations, as a minor, with the laws of conic sections discovered by the Greeks, as a major, premise.This merely shows that a particular

**ellipse**may be described under the law of the direct distance provided the circumstances of projection be suitably adjusted.In elliptic harmonic motion the velocity of P is parallel and proportional to the semi-diameter CD which is conjugate to the radius CP; the hodograph is therefore an

**ellipse**similar to the actual orbit.An

**ellipse**interior to n = a will move in a direction opposite to the exterior current; and when n = o, U = oo, but V = (m/c) sh a sin 13.The velocity of a liquid particle is thus (a 2 - b 2)/(a 2 +b 2) of what it would be if the liquid was frozen and rotating bodily with the

**ellipse**; and so the effective angular inertia of the liquid is (a 2 -b 2) 2 /(a 2 +b 2) 2 of the solid; and the effective radius of gyration, solid and liquid, is given by k 2 = 4 (a 2 2), and 4 (a 2 For the liquid in the interspace between a and n, m ch 2(0-a) sin 2E 4) 1 4Rc 2 sh 2n sin 2E (a2_ b2)I(a2+ b2) = I/th 2 (na)th 2n; (8) and the effective k 2 of the liquid is reduced to 4c 2 /th 2 (n-a)sh 2n, (9) which becomes 4c 2 /sh 2n = s (a 2 - b 2)/ab, when a =00, and the liquid surrounds the**ellipse**n to infinity.The largest is an

**ellipse**of about 60 by 66 ft., but most of the sesi have a diameter of 20-25 ft.Now in a conic whose focus is at 0 we have where 1 is half the latus-rectum, a is half the major axis, and the upper or lower sign is to be taken according as the conic is an

**ellipse**or hyperbola.The latter completely encloses a large area of ground in a semicircle of which Besancon itself is the centre, and the whole of the newer works taken together form an irregular

**ellipse**of which the major axis, lying north-east by south-west, is formed by the Doubs.It possesses thi property that the radius of gyration about any diameter is half thi distance between the two tangents which are parallel to that diameter, In the case of a uniform triangular plate it may be shown that thi momental

**ellipse**at G is concentric, similar and similarly situatec to the**ellipse**which touches the sides of the triangle at their middle points.