20. Five marks exercise problems VII

Let \(A = \{-1, 1\}\) and \(B = \{0, 2\}\). If the function \(f : A \rightarrow B\) defined by \(f(x) = ax + b\) is an onto function? Find \(a\) and \(b\).

 

\(a\) \(=\)

 

\(b\) \(=\)