For each of the functions below, determine and prove whether or not it is injective, surjective, and bijective. 1. f: {0, 1}³ → {0, 1}4 is given by adding a copy of the first bit to the end of the binary string. In other words f(xyz) = xyzx. 2. Let S = {1, 2, 3} and consider g: P(S) → {0, 1, 2, 3} given by g(A) = |A|, where recall that for any set A, |A| denotes its cardinality.

Advanced Engineering Mathematics
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Author:Erwin Kreyszig
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Chapter2: Second-order Linear Odes
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For each of the functions below, determine and prove whether or not it is injective, surjective, and
bijective.
4
1. ƒ : {0, 1}³ → {0, 1}ª is given by adding a copy of the first bit to the end of the binary string.
In other words f(xyz) = xyzx.
2. Let S = {1, 2, 3} and consider g: P(S) → {0, 1, 2, 3} given by g(A) = |A|, where recall that
for any set A, |A| denotes its cardinality.
Transcribed Image Text:For each of the functions below, determine and prove whether or not it is injective, surjective, and bijective. 4 1. ƒ : {0, 1}³ → {0, 1}ª is given by adding a copy of the first bit to the end of the binary string. In other words f(xyz) = xyzx. 2. Let S = {1, 2, 3} and consider g: P(S) → {0, 1, 2, 3} given by g(A) = |A|, where recall that for any set A, |A| denotes its cardinality.
Expert Solution
Step 1

1. f is injective. To see this is true, let us consider a, b in {0,1}3. Assume that f(a)=f(b). This means that all four coordinates of f(a) and f(b) are equal. This means that the first three coordinates are equal and are in the same order. This means that a=b, meaning f is injective.

f is not surjective. To see this, a sequence of the form xyzy {0,1}4. But that element has got no preimage.

So, f is not bijective as f is not surjective. 

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