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Dab tsi ntawm kev sib npaug yog parabola?
Dab tsi ntawm kev sib npaug yog parabola?

Video: Dab tsi ntawm kev sib npaug yog parabola?

Video: Dab tsi ntawm kev sib npaug yog parabola?
Video: Ntawm Tsab ----- Lub Neej Plaub Qaib Ciaj Ncaig Official 2024, Kaum ib hlis
Anonim

Tus qauv qauv yog (x - h)2 = 4p (y - k), qhov kev tsom xam yog (h, k + p) thiab directrix yog y = k - p. Yog tias parabola yog rotated kom nws vertex yog (h, k) thiab nws axis ntawm symmetry yog parallel rau lub x-axis, nws muaj ib tug kev sib npaug ntawm (y - k)2 = 4p (x - h), qhov tsom xam yog (h + p, k) thiab directrix yog x = h - p.

Tsuas yog li ntawd, 4 yam ntawm parabolas yog dab tsi?

∴ Coordinates of vertex = (-2.5, -0.5)

2) Thaum vertex li keeb kwm muaj 4 hom parabola.

Parabola

  • y 2 = 4ax rau a > 0.
  • y 2 = -4ax rau <0, x tej zaum yuav muaj tus nqi tsis zoo lossis xoom tab sis tsis muaj tus nqi zoo.
  • x 2 = 4ay rau a > 0.
  • y 2 = -4ay rau a <0.

Tsis tas li ntawd, qhov sib txawv ntawm parabola yog dab tsi? Cov no peb cov ntaub ntawv tseem ceeb uas peb teeb tsa parabolas los ntawm hu ua standard form, intercept form thiab vertex form.

Nyob rau hauv no hais txog, dab tsi yog 3 daim ntawv ntawm ib tug quadratic muaj nuj nqi?

Nov yog peb daim ntawv sib npaug plaub npaug yuav tsum tau sau rau hauv:

  • 1) Cov qauv qauv: y = ax2 + bx + c qhov twg a, b, thiab c yog cov lej xwb.
  • 2) Factored daim ntawv: y = (ax + c) (bx + d) dua tus a, b, c, thiab d yog cov lej xwb.
  • 3) Vertex daim ntawv: y = a(x + b) 2 + c dua tus a, b, thiab c yog cov lej xwb.

Dab tsi yog 2 hom parabola?

Hom Parabola

  • Los ntawm Concavity: Concave up: a > 0. Concave down: a < 0.
  • Los ntawm tus naj npawb ntawm cov hauv paus hniav: Lwm txoj kev ntawm kev faib cov parabola yog los ntawm tus naj npawb ntawm lub sij hawm tus parabola cuam tshuam nrog cov kab axis. 2 cov hauv paus hniav: > 0. 1 hauv paus: = 0 yog tias lub vertex kov lub axis. 0 cov hauv paus hniav: <0 yog tias ob qho tib si x thiab y axis tsis kov x lossis y axis.

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