ANSWERS TO SUPPLEMENTARY PROBLEMS 373 23.36. See Fig. 23-9. 23.37. See Fig. 23-10. Fig. 23-! Fig. 23-10. 23.38. u(x)-u(x-c) 23.39. See Fig. 23-11. Fig. 23-11. 23.40. See Fig. 23-12. 23.41. Fig. 23-12.