Which of the following gives the correct condition for a function to be surjective (onto)?

MATHEMATICS · Single correct · A Level · Mathematics · Algebra and Functions · Algebra and Functions

Problem

Which of the following gives the correct condition for a function

f:A\to B

to be surjective (onto)? (a) For every

x\in A

, there exists

y\in B

such that

f(x)=y

. (b) For every

y\in B

, there exists a unique

x\in A

such that

f(x)=y

. (c) For every

y\in B

, there exists

x\in A

such that

f(x)=y

. (d) For all

x_1,x_2\in A

f(x_1)=f(x_2)

implies

x_1=x_2