Determine whether each of these functions from Z to Z is one-to-one.
a) f(x) = x−2
b) f(x) = x2 −1
c) f(x) = x3
"a:\\\\f\\left( x \\right) =f\\left( y \\right) \\Rightarrow x-2=y-2\\Rightarrow x=y\\,\\,-\\,\\,yes\\\\b:\\\\f\\left( 1 \\right) =1^2-1=0\\\\f\\left( -1 \\right) =\\left( -1 \\right) ^2-1=0\\\\f\\left( 1 \\right) =f\\left( -1 \\right) \\,\\,-\\,\\,no\\\\c:\\\\f\\left( x \\right) =f\\left( y \\right) \\Rightarrow x^3=y^3\\Rightarrow x=y\\,\\,-\\,\\,yes"
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