Yog tias parabola muaj kab rov tav, tus qauv qauv ntawm qhov sib npaug ntawm parabola yog qhov no: (y - k)2=4p(x - h), qhov twg p≠ 0. Lub vertex ntawm no parabola yog ntawm (h, k). Kev tsom xam yog nyob ntawm (h + p, k). Tus directrix yog kab x=h - p.
Puas yog sideways parabola muaj nuj nqi?
Wikipedia sau tib yam: "Raws li piv txwv, ib sab parabola (ib qho uas nws cov directrix yog ib txoj kab ntsug) tsis yog daim duab ntawm txoj haujlwmvim qee cov kab ntsug yuav sib tshuam lub parabola ob zaug. "
kab rov tav parabola yog dab tsi?
Lub squaring ntawm qhov sib txawv hauv qhov sib npaug ntawm parabola txiav txim siab qhov twg nws qhib: Thaum y yog squared thiab x tsis yog, lub axis ntawm symmetry yog kab rov tav thiab parabola qhib sab laug lossis sab xis. Piv txwv li, x=y2 yog kab rov tav parabola; nws tau pom hauv daim duab.
Koj paub li cas yog parabola yog ntsug lossis kab rov tav?
Yog tus x yog squared, parabola yog ntsug (qhib los yog nqis). Yog tias y yog squared, nws yog kab rov tav (qhib sab laug lossis sab xis). Yog tias qhov zoo, parabola qhib los yog mus rau sab xis. Yog tias nws tsis zoo, nws qhib los yog sab laug.
Koj pom kab rov tav ntawm parabola li cas?
Yog tias parabola muaj kab rov tav, tus qauv qauv ntawm qhov sib npaug ntawm parabola yog qhov no: (y - k)2=4p(x - h), qhov twg p≠ 0. Lub vertex ntawm no parabola yog ntawm (h, k). Kev tsom xam yog nyob ntawm (h + p, k). Tus directrix yog kab x=h - p.
