Chapter 14.3, Problem 20E

Hamilton and Euler Circuits In Exercises 15-20, determine whether an Elder circuit, a Hamilton circuit, or neither would solve the problem.

X-Rays In using X-rays to analyze the structure of crystals, an X-ray diffractometer measures the intensity of reflected radiation from the crystal in thousands of different positions. Consider the complete graph with vertices representing the positions where measurements must be taken. The researcher must decide the order in which to take these readings, with the diffractometer returning to its starting point when finished.