Which function has an inverse that is a function?
A) b(x) = x2 + 3
B) d(x) = –9
C) m(x) = –7x
D) p(x) = |x|
A) b(x) = x2 + 3
B) d(x) = –9
C) m(x) = –7x
D) p(x) = |x|