Calculus Know-It-ALL Quotes

“The relation shown in Fig. 1-1 can be modified to make it a function. We must eliminate two of the three pathways from c in the domain. It doesn't matter which two we take out. If we remove the pathways represented by (c,v) and (c,z), we get the function illustrated in Fig. 1-2.”
― Stan Gibilisco, Calculus Know-It-ALL: Beginner to Advanced, and Everything in Between