Show that f is a function one-to-one, if and only if f(x) = 0 for x=0.
I cannot solve this demonstration, I know that if both elements are the same and their functions are the same, then is one to one, but in this case they only show me one element. Please help.
If and only if just means that if f(0) is NOT 0 then the function is NOT one to one.
It does not mean that if f(0) IS 0, then it is one to one.
1. Hypothesis === if a cow, then a mammal
2. converse === if a mammal then a cow (could be but who knows)
3. inverse === if not a cow then not a mammal (again who knows)
4. contrapositive === if not a mammal then not a cow (TRUE)