Lub luag haujlwm tag nrho yog dab tsi?
Lub luag haujlwm tag nrho yog dab tsi?

Video: Lub luag haujlwm tag nrho yog dab tsi?

Video: Lub luag haujlwm tag nrho yog dab tsi?
Video: Leng Yang - Yog Vim Dab Tsi (Official Full Song | Nkauj Tawm Tshiab) 2020/05/24 2024, Kaum ib hlis
Anonim

A tag nrho muaj nuj nqi yog a muaj nuj nqi uas yog txhais rau txhua qhov ua tau ntawm nws cov tswv yim. Uas yog, itterminates thiab xa ib tug nqi.

Hais txog qhov no, koj yuav ua li cas paub yog tias ib yam dab tsi yog ib qho ua haujlwm?

Thiab, tsis muaj y nyob rau hauv qhov ntau yog cov duab ntawm ntau tshaj ib x hauv domain. Yog ib graph a muaj nuj nqi f paub, nws yooj yim rau txiav txim yog tias tus muaj nuj nqi yog 1-to-1. Siv cov kab rov tav kab xeem. Yog tsis muaj kab rov tav hlais daim duab ntawm tus muaj nuj nqi f ntau li ib point, tiam muaj nuj nqi yog 1-to-1.

Ib yam li ntawd, daim ntawv qhia ib nrab yog dab tsi? Txhais: Ib nrab thiab Total Maps (Functions) ib (tag nrho) muaj nuj nqi (los yog a daim ntawv qhia ), yog tias nws yog sab laug-tag nrho thiab txoj cai-tsim. Qhov no zoo ib yam li hais tias mus ib txhis elementy x∈A x ∈ A muaj raws nraim ib lub elementy∈B y ∈ B nrog (x, y)∈f (x, y) ∈ f.

Tsis tas li ntawd, nws txhais li cas los ua Surjective?

Ib txoj haujlwm yog surjective (mus rau) yog tias txhua daim duab ua tau yog mapped los ntawm tsawg kawg ib qho kev sib cav. Hauv lwm lo lus, txhua lub ntsiab lus hauv codomain muaj non-empty preimage. Equivalently, muaj nuj nqi yog surjective yog nws daim duab yog sib npaug rau nws cov codomain. A qhov tseeb muaj nuj nqi yog ib qho kev txiav txim. Txoj cai txhais yog hauv qab no.

Puas yog qhov khoob muaj nuj nqi Txhaj?

Raws li qhov txhais no, ib qho tsis muaj nuj nqi tsis yog txhaj tshuaj vim ˘f:S→∅ tsis yog ib muaj nuj nqi.

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