Question 476980

A {{{rational}}}{{{ expression}}} is a quotient of two expressions. A rational expression can also be considered as a division; when simplifying a single rational expression, divide the numerator by the denominator.

For any rational number or rational expression, the number or expression is {{{undefined}}}{{{ if}}} the {{{denominator}}} is {{{equal}}} to {{{0}}}.


so, {{{rational}}}{{{ expression}}} {{{1/(z-1)}}} is {{{undefined}}} if {{{z-1=0}}} or {{{z=1}}}.