Yuav ua li cas koj hloov ib tug muaj nuj nqi rau hauv vertex daim ntawv?
Yuav ua li cas koj hloov ib tug muaj nuj nqi rau hauv vertex daim ntawv?

Video: Yuav ua li cas koj hloov ib tug muaj nuj nqi rau hauv vertex daim ntawv?

Video: Yuav ua li cas koj hloov ib tug muaj nuj nqi rau hauv vertex daim ntawv?
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Hloov ua lwm yam y = ax2 + bx + c daim ntawv rau vertex daim ntawv y = a(x - h)2+ k, koj siv cov txheej txheem ua kom tiav cov square. Cia peb saib ib qho piv txwv. Hloov y = 2 x2 - 4x + 5 rau hauv daim ntawv vertex , thiab hais cov vertex . Equation in y = ax2 + bx + c daim ntawv.

Hauv qhov no, koj yuav hloov pauv daim ntawv cuam tshuam li cas rau daim ntawv vertex?

Hloov y = 9 x² - 12 x + 1 cuam tshuam daim ntawv . Peb ua tau hloov quadratic muaj nuj nqi los ntawm tus qauv daim ntawv , y = ax² + bx + c, to the general vertex daim ntawv : y = a(x + p)² + q.

Tsis tas li ntawd, koj yuav nrhiav tau lub vertex li cas? Cov kauj ruam los daws

  1. Tau qhov sib npaug hauv daim ntawv y = ax2 + bx + c.
  2. xam -b/2a. Qhov no yog x-coordinate ntawm lub vertex.
  3. Txhawm rau nrhiav y-coordinate ntawm lub vertex, tsuas yog ntsaws tus nqi ntawm -b / 2a rau hauv kab zauv rau x thiab daws rau y. Qhov no yog y-coordinate ntawm lub vertex.

Yog li ntawd, dab tsi yog daim ntawv cuam tshuam ntawm parabola?

Zaj Lus Qhia. Ib zaug ntxiv, cov intercept daim ntawv ntawm ib tug parabola y = a (x - r)(x - s), qhov twg r thiab s yog x- cuam tshuam , lossis qhov twg daim duab hla dhau ntawm x-axis. Qhov txiaj ntsig ntawm kev siv lub cuam tshuam daim ntawv yog tias koj tuaj yeem nrhiav tau yooj yim x- cuam tshuam tsis muaj factoring lossis siv cov qauv quadratic.

Dab tsi yog qhov sib npaug los nrhiav qhov vertex?

Parabola ib txwm muaj qhov qis tshaj plaws (los yog qhov siab tshaj plaws, yog tias parabola yog upside-down). Lub ntsiab lus no, qhov twg parabola hloov kev coj, hu ua " vertex ". Yog hais tias lub quadratic sau nyob rau hauv daim ntawv y = a(x – h)2 + k, tom qab ntawd vertex yog lub ntsiab lus (h, k).

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