Question

True or false,if f(s)=f(t) then s=t​

Answer 1

This is not always true
For example if f = x^2 then
If s = 1 then f(s) = 1 and if t = -1 then f(t) = 1 also
So here we have f(s) = f(t) but s is not = t.
So your answer is
False.