Answer:
• If the equations of a and b are polynomials, it'll be a curve between a and b [ b<x<a ]
• If the equations of a and b are linear, it'll be a line between a and b
[tex]{ \rm{x > a \: \: and \: \: x < b}} \\ \\ { \boxed{ \rm{ \: b < x < a \: }}}[/tex]