Let $\displaystyle f: A \rightarrow B $ be a function. We use f to define a relation $\displaystyle R_f $ on A as follows;

For $\displaystyle a,b \epsilon A, $ $\displaystyle a R_f b $ if and only if f(a) = f(b).

a. What is this relation when f is a one to one function?

b. What is this relation when f is a constant function?

Can anyone tell me where to start?