Relations and Functions Worksheet - Definition, Question with Answer ... Relations and Functions Worksheet Answer Key 1. Set P = {-2,0,2} and the remaining elements are { (-2,-2), (-2,2), (0,-2), (0,0), (2,-2), (2,0), (2,2)} 2. As all the 120 students belong to class 11, every pupil must be in any of the sections. So, this relation is a function as well. 3. f-1 (x) = (9x/5) + 32 and the inverse is a function also. 4.