16)Let f be a function from R to R defined by \(f(x) = 3x - 5\). Find the values of a and b given that (a,4) and (1,b) belong to f.
Answer: \(f(x) = 3x - 5\) can be written as \(f = \{(x, 3x-5) | x \in R\}\).
(a, 4) means the image of a is 4. That is, f(a) = 4
\(3a - 5 = 4 \Rightarrow 3a = 9 \Rightarrow a = 3\)
(1, b) means the image of 1 is b. That is, f(1) = b
\(3(1) - 5 = b \Rightarrow b = -2\)