Discrete Mathematics Homework
1.4.37
(a)x^2≥x means x(x-1)≥0,and all integers satisfy it. So there isn’t any
counterexample.
(b)If x=0,then x>0 and x<0 are both false. So x=0 is a counterexample.
(c)If x=0,then x≠0. So x=0 is a counterexample.
1.5.15
(a)∀xP(x), x:a computer science student in this class, P(x):x needs a
course in discrete mathematics.
(c)∀x∃yP(x,y), x:a student in this class, y:a computer science course,
P(x,y):x has taken y.