Yuav ua li cas koj nrhiav tau lub cim sawv cev ntawm ib tug quadratic muaj nuj nqi?
Yuav ua li cas koj nrhiav tau lub cim sawv cev ntawm ib tug quadratic muaj nuj nqi?

Video: Yuav ua li cas koj nrhiav tau lub cim sawv cev ntawm ib tug quadratic muaj nuj nqi?

Video: Yuav ua li cas koj nrhiav tau lub cim sawv cev ntawm ib tug quadratic muaj nuj nqi?
Video: Yuav ua li cas thiaj khiav dim lub ntiajteb no 2024, Kaum ib hlis
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Quadratic muaj nuj nqi tuaj yeem sawv cev cim los ntawm kev sib npaug , y(x) = ax2 + bx + c, qhov twg a, b, thiab c yog qhov tsis tu ncua, thiab a ≠ 0. Daim ntawv no raug xa mus rau daim ntawv qauv.

Tib neeg kuj nug, dab tsi yog lub cim qhia txog kev ua haujlwm?

Muaj nuj nqi . Tej zaum koj feem ntau paub txog cov cim sawv cev ntawm muaj nuj nqi , xws li equation, y = f(x). Muaj nuj nqi tuaj yeem sawv cev los ntawm cov rooj, cim , los yog graphs.

Ib yam li ntawd, koj yuav txiav txim siab li cas ntawm daim duab plaub? Cov duab ntawm parabola

  1. Yog tias a> 0, ces tus parabola muaj qhov tsawg kawg nkaus taw tes thiab nws qhib upwards (U-shaped) xws li.
  2. Yog tias a <0, ces tus parabola muaj qhov siab tshaj plaws thiab nws qhib downwards (n-shaped) xws li.
  3. (a) Xyuas seb a> 0 lossis a <0 los txiav txim seb nws puas yog U-shaped lossis n-shaped.
  4. (c) Cov kev tswj hwm ntawm y-intercept (hloov x = 0).

Yog li ntawd, koj yuav ua li cas sawv cev rau lub quadratic muaj nuj nqi?

Cov duab. A quadratic muaj nuj nqi yog ib daim foos f(x) = ax2 + bx + c, qhov twg a, b, thiab c yog cov lej uas tsis sib npaug rau xoom. Graph ntawm a quadratic muaj nuj nqi yog ib qho nkhaus hu ua parabola. Parabolas tuaj yeem qhib sab saud lossis nqes thiab sib txawv hauv "dav" lossis "seepness", tab sis lawv txhua tus muaj tib yam "U" duab.

Koj yuav daws tau qhov ua haujlwm li cas?

Rau muaj nuj nqi , ob lub ntsiab lus txhais tau hais tias tib yam nkaus, tab sis "f (x)" muab rau koj yooj yim dua thiab cov ntaub ntawv ntau ntxiv. Koj tau hais tias "y = 2x + 3; daws rau y thaum x = –1” Tam sim no koj hais "f (x) = 2x + 3; nrhiav f (–1)" (hais tias "f-ntawm-x sib npaug 2x ntxiv rau peb; nrhiav f-of-negative-one").

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