Cov kab ntawm cov haujlwm muaj npe muaj qee yam tshwj xeeb uas tsis meej uas tsis muaj kev sawv cev pom. Ib qho ntawm cov yam ntxwv no yog cov kab sib npaug, kab ntsug uas faib cov duab ua ob sab sib npaug. Nrhiav lub axis ntawm symmetry ntawm polynomial muaj nuj nqi yog qhov yooj yim, vim muaj ob txoj hauv kev yooj yim rau qhov no.
cov kauj ruam
Txoj Kev 1 ntawm 2: Nrhiav lub axis ntawm symmetry ntawm qib 2 polynomials
Kauj Ruam 1. Txheeb xyuas qib kawm ntawm tus lej polynomial hauv nqe lus nug
Qhov kawm tiav (lossis xaj) ntawm ntau tus lej yog qhov tseem ceeb tshaj plaws nthuav tawm tam sim no hauv kev qhia. Yog tias qib ntawm polynomial yog 2 (uas txhais tau tias tsis muaj tus lej nthuav tawm ntau dua x2), koj tuaj yeem pom lub axis ntawm symmetry siv txoj hauv kev no. Yog tias qib ntawm polynomial ntau dua 2, siv Txoj Kev 2.
Txhawm rau ua piv txwv, cia li siv 2x polynomial ua piv txwv2 + 3x - 1. Qhov loj tshaj plaws ntawm kev nthuav qhia yog x2, yog li nws yog qhov kev txiav txim zaum thib ob polynomial, uas tso cai rau koj siv txoj hauv kev no txhawm rau nrhiav lub axis ntawm symmetry.
Kauj Ruam 2. Hloov koj tus lej rau hauv cov lej sib npaug
Txhawm rau xam lub axis ntawm qhov sib npaug ntawm qhov kev txiav txim zaum thib ob polynomial ntawm daim ntawv ax2 + bx + c (a parabola), siv cov qauv x = -b / 2a.
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Hauv qhov piv txwv saum toj no, a = 2 b = 3 thiab c = -1. Hloov qhov tseem ceeb thiab koj yuav pom:
x = -3 / 2 (2) = -3/4.
Kauj Ruam 3. Sau cov kab zauv sib npaug
Tus nqi uas koj suav nrog siv cov mis saum toj no sawv cev rau qhov chaw uas cov kab sib npaug sib npaug txiav lub x axis.
Hauv qhov ua piv txwv saum toj no, txoj kab sib luag yog kab x = -3/4
Txoj Kev 2 ntawm 2: Nrhiav lub axis ntawm symmetry graphically
Kauj Ruam 1. Txheeb xyuas qib kawm ntawm tus lej polynomial hauv nqe lus nug
Qhov kawm tiav (lossis xaj) ntawm ntau tus lej yog qhov tseem ceeb tshaj plaws nthuav tawm tam sim no hauv kev qhia. Yog tias qib ntawm polynomial yog 2 (uas txhais tau tias tsis muaj tus lej nthuav tawm ntau dua x2), koj tuaj yeem pom lub axis ntawm symmetry siv cov txheej txheem saum toj no, uas siv cov mis. Txawm li cas los xij, yog tias qib kawm siab dua 2, siv cov txheej txheem no.
Kauj Ruam 2. Kos x thiab y axes
Ua ob kab hauv daim ntawv ntawm "+" kos npe. Kab rov tav yuav yog x axis thaum txoj kab ntsug yuav yog y axis.
Kauj Ruam 3. Teev daim ntawv qhia
Kos ob kab nrog cov lej tawm qhov sib npaug ntawm lawv.
Kauj Ruam 4. Xam y = f (x) rau txhua tus nqi ntawm x
Siv cov lej ua haujlwm los laij cov nuj nqis ntawm f (x) los ntawm kev hloov qhov tseem ceeb ntawm x rau hauv nws.
Kauj Ruam 5. Ua tus lej ntawm kab ntawv rau txhua khub
Tam sim no koj yuav muaj tus nqi y = f (x) rau txhua tus nqi ntawm x. Rau txhua tus (x, y) khub, ua tus taw tes rau ntawm kab kos cim qhov chaw sib tham los ntawm kev mus ntsug ntawm x-axis thiab kab rov tav ntawm y-axis.
Kauj Ruam 6. Kos cov duab polynomial
Tom qab khij txhua lub ntsiab lus ntawm kab ntawv, koj tuaj yeem txuas lawv tag nrho ua ke los qhia qhov teeb meem txuas mus ntxiv ntawm cov lej.
Kauj Ruam 7. Nrhiav lub axis ntawm symmetry
Saib daim ntawv ua tib zoo. Nrhiav qhov taw tes ntawm nws qhov twg, yog tias kab tau kos, daim duab yuav muab faib ua ob qhov sib npaug sib npaug.
Kauj Ruam 8. Paub lub axis ntawm kev sib luag
Yog tias koj tuaj yeem pom qhov taw tes, cia peb hu nws "b", ntawm x-axis, qhov twg kab hla nws yuav faib cov duab ua ob daim iav sib npaug sib npaug, tom qab ntawd kab x = b yog kab sib dhos uas koj tab tom nrhiav.
Lub tswv yim
- Qhov loj ntawm x thiab y axis yuav tsum loj txaus kom tso cai teeb duab kom pom tseeb.
- Qee qhov polynomials tsis sib thooj. Piv txwv li polynomial y = 3x, piv txwv li, tsis muaj axis ntawm symmetry.
- Qhov sib npaug ntawm polynomial tuaj yeem muab cais ua qhov txawm lossis txawv. Ib daim duab uas muaj ib txoj kab sib luag ntawm y-axis muaj qhov sib npaug. Yog tias symmetry nyob ntawm x-axis, nws yuav txawv.