surjective
Significado: Describing a function in which every element of the codomain is mapped to by at least one element of the domain, ensuring that the function's range equals its entire codomain. Also called onto.
A surjective function 'covers' its entire codomain — no element of the target set is left unmapped. Surjectivity is crucial when proving that a function has a right inverse and in establishing correspondences between sets. Combined with injectivity, it yields bijectivity. The concept arises naturally in linear algebra (where surjective linear maps are those whose image spans the entire codomain) and in algebraic topology. Like 'injective' and 'bijective,' the term is confined to mathematical and computer science discourse.
Ejemplos
- The function f(x) = x² mapping real numbers to non-negative reals is surjective because every non-negative number has a square root. 函数f(x) = x²从实数映射到非负实数是满射的,因为每个非负数都有平方根。La función f(x) = x² que aplica los números reales sobre los reales no negativos es sobreyectiva porque todo número no negativo tiene una raíz cuadrada.関数f(x) = x²は実数から非負実数への写像として全射である。なぜなら、すべての非負数には平方根が存在するからである。함수 f(x) = x²은 실수에서 비음수 실수로의 사상으로서 전사이다. 모든 비음수에는 제곱근이 존재하기 때문이다.
- The proof required showing that the homomorphism was surjective, meaning every element in the quotient group had a preimage. 该证明需要证明同态映射是满射的,意味着商群中的每个元素都有原像。La demostración requería mostrar que el homomorfismo era sobreyectivo, es decir, que todo elemento del grupo cociente tenía una preimagen.その証明では、準同型写像が全射であること、すなわち商群のすべての要素に原像が存在することを示す必要があった。그 증명에서는 준동형 사상이 전사임을, 즉 상군의 모든 원소에 원상이 존재함을 보여야 했다.
- A surjective mapping from job applicants to interview slots ensures that every available slot is filled by at least one candidate. 从求职者到面试时间段的满射映射确保每个可用时间段都至少被一位候选人填满。Una correspondencia sobreyectiva de los candidatos a los huecos de entrevista garantiza que todas las franjas disponibles están ocupadas por al menos un candidato.求職者から面接枠への全射写像は、利用可能なすべての枠が少なくとも一人の候補者で埋められることを保証する。구직자에서 면접 시간대로의 전사 사상은, 사용 가능한 모든 시간대가 적어도 한 명의 지원자로 채워짐을 보장한다.
Pronunciación
Guía de uso
Contexto: scientific, academic
Tono: neutral
Origen e historia
From French surjection, coined by the Bourbaki group in the mid-20th century from the prefix sur- (over, upon, from Latin super) and the Latin-derived -jection (throwing), from jacere (to throw).
Contexto cultural
Era: Modern
Generation: All ages
Social background: Universal
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