Koj tuaj yeem qhia tau li cas yog tias kev sib raug zoo yog symmetrical?
Koj tuaj yeem qhia tau li cas yog tias kev sib raug zoo yog symmetrical?

Video: Koj tuaj yeem qhia tau li cas yog tias kev sib raug zoo yog symmetrical?

Video: Koj tuaj yeem qhia tau li cas yog tias kev sib raug zoo yog symmetrical?
Video: Tag Kis Tsis Muaj Koj - Lig Muas Nkauj Tawm Tshiab 2022 2024, Kaum ib hlis
Anonim

A kev sib raug zoo yog symmetrical , peb soj ntsuam uas rau tag nrho cov nqi ntawm a thiab b: a R b implies b R a. Cov kev sib raug zoo ntawm kev sib npaug dua yog symmetrical . Yog x=y, peb kuj sau tau uas y = x.

Ib yam li ntawd, nws txhais li cas rau kev sib raug zoo kom sib luag?

A symmetrical kev sib raug zoo yog ib hom binary kev sib raug zoo . Ib qho piv txwv yog tus kev sib raug zoo " yog equal to", vim yog a = b yog true ces b = a yog kuj muaj tseeb. Raws li txoj cai, binary kev sib raug zoo R dhau ib teev X yog symmetrical yog tias thiab tsuas yog: Yog RT sawv cev rau lub converse ntawm R, ces R yog symmetrical yog thiab tsuas yog R = RT.

Qhov thib ob, kev sib raug zoo puas tuaj yeem sib luag thiab tsis sib haum? A kev sib raug zoo tau ua ob leeg symmetrical thiab antisymmetrical , npr kev sib raug zoo ntawm kev sib npaug. Nws yog symmetrical txij li a=b?b=a tab sis kuj yog antisymmetrical vim koj muaj ob qho tib si a=b thiab b=a iff a=b (oh, zoo).

Tsuas yog li ntawd, koj ua li cas txiav txim siab hloov pauv thiab hloov pauv symmetrical?

  1. Reflexive. Kev sib raug zoo yog reflexive. Yog tias (a, a) ∈ R rau txhua ∈ A.
  2. Symmetrical. Kev sib raug zoo yog sib npaug, Yog tias (a, b) ∈ R, ces (b, a) ∈ R.
  3. Kev hloov pauv. Kev sib raug zoo yog hloov pauv, Yog tias (a, b) ∈ R & (b, c) ∈ R, ces (a, c) ∈ R. Yog hais tias kev sib raug zoo yog reflexive, symmetric thiab transitive, nws yog qhov sib npaug sib npaug. Cia peb ua piv txwv.

4 hom symmetry yog dab tsi?

Cov plaub lub ntsiab hom ntawm no symmetry yog txhais, rotation, reflection, thiab glide reflection.

Pom zoo: