Cov txheej txheem:

Yuav ua li cas ua ib lub cubic graph?
Yuav ua li cas ua ib lub cubic graph?

Video: Yuav ua li cas ua ib lub cubic graph?

Video: Yuav ua li cas ua ib lub cubic graph?
Video: Yuav ua li cas thiaj khiav dim lub ntiajteb no 2024, Kaum ib hlis
Anonim

Yog hais tias qhov sib npaug yog nyob rau hauv daim ntawv y = (x − a)(x − b)(x − c) yuav tsum siv txoj hauv qab no:

  1. Nrhiav cov x-intercepts los ntawm kev muab y = 0.
  2. Nrhiav y-intercept los ntawm kev muab x = 0.
  3. Npaj cov ntsiab lus saum toj no los kos duab kub nkhaus.
  4. Nrhiav cov x-intercepts los ntawm kev muab y = 0.
  5. Nrhiav y-intercepts los ntawm kev muab x = 0.

Kuj nug, ua li cas koj sau lub cubic muaj nuj nqi?

A kub function muaj cov qauv ntawm f(x) = ax3 + bx ib2 + cx + d. Qhov "basic" kub function yog f(x) = x3. Koj tuaj yeem pom nws hauv daim duab hauv qab no. Hauv ib kub function , lub zog siab tshaj ntawm x sib txawv (s) yog 3.

Tsis tas li ntawd, qhov piv txwv cubic function yog dab tsi? A kub function yog ib qho muaj nuj nqi ntawm daim ntawv y = ax^3 + bx^2 + cx + d, qhov twg a, b, c, thiab d yog qhov tsis tu ncua, thiab a tsis sib npaug rau xoom, lossis a polynomial ua haujlwm nrog lub siab tshaj plaws exponent sib npaug 3. Cov hom ntawm muaj nuj nqi muaj ntau heev nyob rau hauv daim ntawv thov uas muaj ntim.

Ib yam li ntawd, koj ua li cas hloov cov duab cubic?

Yog tias y = f(x + d) thiab d > 0, the daim duab undergoes kab rov tav ua haujlwm d units mus rau sab laug. Yog tias y = f(x + d) thiab d <0, the daim duab undergoes kab rov tav ua haujlwm d units mus rau sab xis.

Dab tsi yog daim duab ntawm lub cubic muaj nuj nqi hu ua?

A kub function (a.k.a. thib peb-degree polynomial muaj nuj nqi ) yog ib qho uas tuaj yeem sau rau hauv daim ntawv. f(x) = ax3 + bx2 + cx + d. (1) Quadratic muaj nuj nqi tsuas yog tuaj nyob rau hauv ib qho yooj yim duab, ib tug parabola. Lub parabola tuaj yeem ncab lossis compressed.

Pom zoo: