Yuav ua li cas koj kos ib lub conic ntawm ib tug parabola?
Yuav ua li cas koj kos ib lub conic ntawm ib tug parabola?

Video: Yuav ua li cas koj kos ib lub conic ntawm ib tug parabola?

Video: Yuav ua li cas koj kos ib lub conic ntawm ib tug parabola?
Video: yuav coj li cas kom luag nyiam 2024, Kaum ib hlis
Anonim

Cov directrix yog kab y = k - p. Lub axis yog kab x = h. Yog tias p> 0, lub parabola qhib upward, thiab yog p <0, lub parabola qhib nqes. Yog ib parabola muaj kab rov tav axis, tus qauv daim ntawv ntawm qhov sib npaug ntawm cov parabola yog qhov no: (y - k)2 = 4p(x - h), p≠ 0.

Tsis tas li ntawd, dab tsi yog conic seem parabola?

< Conic Sections . Cov parabola yog lwm tus paub conic seem . Geometric txhais ntawm a parabola yog qhov chaw ntawm tag nrho cov ntsiab lus xws li tias lawv sib npaug ntawm qhov taw tes, hu ua kev tsom, thiab ib txoj kab ncaj nraim, hu ua directrix. Hauv lwm lo lus, eccentricity ntawm a parabola yog 1.

Qhov thib ob, koj yuav txheeb xyuas qhov conic li cas? Yog hais tias lawv yog, ces cov yam ntxwv no yog raws li nram no:

  1. Lub voj voog. Thaum x thiab y yog ob qho tib si squared thiab cov coefficients ntawm lawv yog tib yam - nrog rau cov kos npe.
  2. Parabola. Thaum twg x lossis y yog squared - tsis yog ob qho tib si.
  3. Ellipse. Thaum x thiab y yog ob qho tib si squared thiab cov coefficients zoo tab sis txawv.
  4. Hyperbola.

Kuj paub yog, qhov sib npaug ntawm parabola yog dab tsi?

Muab qhov tsom xam (h, k) thiab directrix y = mx + b, the kev sib npaug rau a parabola yog (y - mx - b)^2 / (m^2 + 1) = (x - h)^2 + (y - k)^2.

Yuav ua li cas yog parabola tsim?

A parabola yog qhov nkhaus tsim los ntawm kev sib tshuam ntawm lub dav hlau thiab lub khob hliav qab, thaum lub dav hlau nyob ntawm tib lub slant ib sab ntawm lub khob hliav qab.

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