pls show me your work

In Problems 15-22, use the given information to sketch the graph off. Assume that f is continuous on its domain and that all inter- cepts are included in the table of values. 15. Domain: All real x; lim f(x) = 2 -4 -2 0 f(x) 0 -2 0 -2 f(x) - - -----0+++ND- --0+ + + + + ++ 0 2 F(x) - - - 0+ + ++++ ND + + + +++0 - = = 21. Domain: All real x, except x = -2 and x = 2; f(-3) = -1,f(0) = 0, f(3) = 1; f' (x) 0on (-2, 2); f"(x) 0 on (0, 2) and (2, co ); 79. Revenue. The marketing research department for a computer company used a large city to test market the firm's new lap- top. The department found that the relationship between price p (dollars per unit) and demand x (units sold per week) was given approximately by p = 1,296 - 0.12x2 0= x = 80 So, weekly revenue can be approximated by R(x) = xp = 1,296x - 0.12x3 OS X = 80 Graph the revenue function R