I-sign (yakwamathematika)

KwaMathematika, igama elithi **sign** libhekisa kuyo yonke into ebonakalisa ukuba-positive (ukwanda okanye ukuba negative (ukuncipha). Naliphi na inani   eliyi-real number (inani elingengo-0) linga-pisitive okanye libe-negative, lithi ke ngoko libe ne-sign. UZero yena eyedwa akanayo i-sign, singathi mhlawumbi. Ukongeza kwi-sign ebekwa kwii-real numbers (kumanani angengozero), igama elithi sign lisetyenziswa kwimathematika yonke iphela ukubonisa iindima ngeendima zemathemathika ezithetha ubu-positivity kwanobu-negativity. into eqhele ukwenzeka, kukuba xa amanani ebonakala engaphandle kwe-sign, abonakala engamanani a-positive (kuthiwe zii-positive numbers).

Igama elithi sign maxa wambi lisoloko lisetyenziswa xa kubhekiswa kwiintlobo-ntlobo zee-signs zakwamathematika, ezinjengo-plus kunye no-minus kunye ne-sign yo-kuphindaphinda (ekuthiwa yimultiplication sign). 

## I-Sign yenani
I-real number kuthiwa i-positive ukuba ingaphezulu ko-zero, ize ibe-negative ukuba ingaphantsi ko-zero. Uphawu lokuba positive nokuba negative kuthiwa yi-**sign** yenani. U-Zero xa eyedwa akafanelekanga kuba na-sign.

Kwiarithmetic, i-sign yenani isoloko iboniswa ngokubeka i-sign okanye uphawu luka-plus okanye oluka-minus phambi kwenani. umzekelo, u- +3 uthetha u 3 opositive, aze u −3 athethe u 3 o-negative. ukuba akukho sign engu-plus okanye engu-minus enikiweyo, inye kuphela indlela elingabonwa ngayo eli nani yeyokokuba li-positive.  

I-sign yenani elingengo-zero isengatshintshwa ibe positive xa kusetyenziswa iabsolute value function. Umzekelo, i-absolute value ka−3 kunye ne-absolute value ka 3 zombini ziyalingana no-3.  Ngokwee-symbols, oku kungabhalwa ngolu hlobo |−3| = 3 and |3| = 3.

### I-Sign ka-zero
Inani u-zero alikwazi ukuba -positive nokuba-negative, ngoko ke alinayo isign.  Kwa-arithmetic,u +0 no −0 omabini athetha inani elinye elingu-0.

## Intsingiselo yee-signs
Ngenxa yokokuba u-zero engekho positive na-negative, oku kulandelayo kuye kuthi ngamanye amaxesha kubizwe ngokuba kuyi-sign yenani elingaziwayo:  
* Inani li-**positive** ukuba lingaphezu kuka-zero.
* Inani li-**negative** ukuba linhaphantsi kuka-zero.
* Inani li-**non-negative** ukuba lingaphezulu okanye lilingana no-zero.
* Inani li-**non-positive** ukuba lingaphantsi okanye lilingana no-zero.
Loo nto ithetha okokuba inani eli non-negative number lisenokuba positive okanye libe ngu-zero, ngeli lixa lona inani eli-non-positive lisenokuba negative okanye libe ngu-zero.  Umzekelo, i-absolute value ye-real number isoloko i-non-negative, kodwa loo nto isenokungathethi into yokokuba li- positive.

Kwale ngcaciso inye iyasetyenziswa ngamanye amaxesha ukwenza iifunctions ezithatha i-real numbers okanye ii-integer values. Umzekelo, i-function ingabizwa ngokuba i-positive ukuba zonke ii-values zayo zi-positive, okanye kungathiwa i-non-negative ukuba zonke iivalues zayo zi-non-negative.

### I-Sign ye-angle (yegophe)

Kwimibhalo emininzi, kuxhaphakile ukubona i-sign ikunye nomlinganiselo we-angle, ingakumbi i-angle e-located okanye i-angle ye-rotation.  kulo meko injalo, i-sign iyaxela ukuba i-angle ikwi-clockwise okanye i-counterclockwise direction.  Nangona zikho ezinye indlela ngendlela ezinokusetyenziswa, kuxhaphakile kwi-mathematika ukuba kubekho ii-angles ezizii-counterclockwise ezibala njenge-positive, neeangles ezizii-clockwise ezibala njenge-negative.

Kwakhona kuyenzeka okokuba kubekwe i-sign kwi-angle ye-rotation ngee-dimensions ezintathu, uqikelelwa okokuba i-axis of rotation has been oriented.  Xa sigqalisela, igophe elijikelezela ngasekunene lijikeleze i-axis lisoloko libala njengeli-positive, ngeli lixa lijikelezela ngasekhohlo libala njngeli-negative.

### I-Sign ye-direction
Kwiarithmetic nakwi-fiziki, kuxhaphakile ukuthiya ii-directions ezithile ngelithi zi-positive okanye zi-negative. Nanku umzekelo olula,   umgca-manani ekuthiwa yi-number line ngesilungu usoloko uzotywa ubenamanani a-positive ukuya ngasekunene, aze abe-negative amanani xa kusiyiwa ngasekhohlo: 

Kwi-Cartesian plane, ii-directions ziya  ngasekunene nezibheka phezulu kusoloko kucingwa okokuba zi-positive, kuba ukubheka ngasekunene kuba-positive, i-*x*-direction, nokubheka phezulu kukuba-positive i-*y*-direction.

### Ezinye iintsingiselo

Ukongeza kwi-sign ye-real number, igama elithi sign likwasetyenziswa  ngeendlela ezahlukeneyo kodwa zikwasengela thungeni linye kwiMathematika iphela nakwizifundo ze-science ngokubanzi:
* Kw-i-graph theory, i-grafu e-signed yi-grafu enomda ophawuliwe ngophawu olu-positive nolu-negative. 
* Kwifiziki, nakuphi na ukutshaja kombane kuza ngophawu, olusenokuba-positive okanye lube-negative.  Ngokwemithetho jikelele, ukutshaja oku-positive, kukutshaja okunophawu olufanayo noluya lwe-proton, kwaye ukutshaja oku-negative charge kukutshaja okufanayo nophawu lwe-electron.