Dab tsi yog tus qauv los nrhiav foci?
Dab tsi yog tus qauv los nrhiav foci?

Video: Dab tsi yog tus qauv los nrhiav foci?

Video: Dab tsi yog tus qauv los nrhiav foci?
Video: txoj kev hlub yog dab tsi by nkaujlig hawj new song 5/17/2020 2024, Kaum ib hlis
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Txhua lub ellipse muaj ob foci ib (plural ntawm tsom ) raws li qhia hauv daim duab ntawm no: Raws li koj tuaj yeem pom, c yog qhov kev ncua deb ntawm qhov chaw mus rau a tsom . Peb ua tau nrhiav tus nqi ntawm c los ntawm kev siv cov qauv c2 = a2 -b2. Pom tias qhov no qauv muaj ib tug tsis zoo kos npe rau, tsis yog ib tug zoo kos npe rau zoo li lub qauv rau hyperbola.

Ntawm no, koj yuav nrhiav tau lub foci li cas?

Qhov tseeb, ellipse yog txiav txim los ntawm nws foci ib . Tab sis yog tias koj xav txiav txim qhov foci ib koj tuaj yeem siv qhov ntev ntawm qhov loj thiab me axes rau nrhiav nws coordinates. Cia peb hu ib nrab qhov ntev ntawm cov axis loj a thiab ntawm cov axis me b. Ces qhov deb ntawm lub foci ib los ntawm qhov chaw yuav sib npaug rau^2-b^2.

Ib qho ntxiv, dab tsi yog foci ntawm ellipse? Foci ntawm Ellipse . Ob lub ntsiab lus ruaj khov ntawm sab hauv ntawm ib qho ellipse siv nyob rau hauv lub formal txhais ntawm lub nkhaus. Ib ellipse yog txhais raws li hauv qab no: Rau ob lub ntsiab lus muab, tus foci ib , ib ellipse yog qhov chaw ntawm cov ntsiab lus xws li qhov sib npaug ntawm qhov kev ncua deb mus rau txhua qhov kev tsom mus tas li.

Ib yam nkaus, dab tsi yog qhov sib npaug los nrhiav foci ntawm hyperbola?

Cov toj siab thiab foci ib yog nyob rau x-axis. Yog li ntawd, lub kev sib npaug rau cov hyperbola y y 2 b 2 = 1 x 2 a 2 − y 2 b 2 = 1. Cov ntsug yog (± 6, 0) (± 6, 0), yog li a = 6 a = 6 thiab a2 = 36 a 2 = 36. Cov foci ib yog (± 2√10, 0) (± 2 √10, 0), c=2√10 c = 2 10 c2 = 40 c 2 = 40.

Yuav ua li cas koj pom cov foci thiab vertices ntawm lub ellipse?

Nrhiav cov kev sib npaug ntawm ib ellipse nrog toj siab (0, ± 8) thiab foci ib (0, ± 4). Cov kev sib npaug ntawm ib ellipse yog (x − h) 2a2+(y − k) 2b2 = 1 rau txoj kab rov tav ellipse thiab (x − h) 2b2+(y − k) 2a2 = 1 rau kev teeb tsa ntsug ellipse.

Pom zoo: