Editing Ordinal utility (section)

== Linearity ==
When the MRS of a certain preference relation does not depend on the bundle, i.e., the MRS is the same for all <math>(x_0,y_0)</math>, the indifference curves are linear and of the form:
:<math>x+\lambda y = \text{const},</math>
and the preference relation can be represented by a linear function:
:<math>v(x,y)=x+\lambda y.</math>
(Of course, the same relation can be represented by many other non-linear functions, such as <math>\sqrt{x+\lambda y}</math> or <math>(x+\lambda y)^2</math>, but the linear function is simplest.)<ref name=KeeneyRaiffa1993/>{{rp|85}}