- #1
sunnyday11
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Homework Statement
Decide with proof whether the mapping is injective and/or surjective.
Let f: A-->B be a mapping.
h: C--> C; h(x)=x3 + x (complex field)
f: Z--> Z; h(x)=x3 + x (integer field)
Homework Equations
injective means f(a)=f(a') => a=a'
surjective means for all b belong to B, there exists a belong to A such that f(a)=b
The Attempt at a Solution
For injectivity, I sub a and a' into equations h and f but I have no idea how to equate them or to prove them false.
For subjectivity the same issue arises, I try to get a inverse of the equation since I think they are surjective and can't think of any example to contradict it.
Thank you very much!