1. The problem statement, all variables and given/known data Let f be a function from A to B and g a function from B to C. Show that if the composite function g°f is one-one, then f is one-one. 2. Relevant equations 3. The attempt at a solution By definition of a function every value of A has to be maped to a value in B. Likewise every value of B has to be maped to a value in C. So by definition of 1-1... since g°f satisfies this rule and g°f is a composite function... Therefore f must be 1-1. Does this make a valid argument? and justify the answer?