If f1(x) = a1x+b1 with a1 0 and f2(x) = a2x+b2 with a2 o, show that f1(f2(x) ) = Ax+B, with A 0, and find the constant A and B. Deduce from Exercise 5. 5. 1 that the result of composing any number of functions that send x to x=1 or kx (for k 0) is a function of the form f(x) =ax+b with a o. We know that such functions represent combinations of projections from lines to parallel lines, but do they include any projection from a line to a parallel line?