We learned how to work with linear inequalities with one unknown and with two unknowns.

An exact description of the solutions of linear inequalities with two unknowns is provided with the aid of intervals for #x# at each value of #y# , or vice versa (with #x# and #y# interchanged). In the example, this would be the union of the intervals #\ivoo{-\infty}{\frac{7}{2}-\frac{3}{2}y}# of #y#. More information can be found in the chapter on Collections.

In the chapter polynomial functions and rational functions, we will look at inequalities that carry quadratic polynomials, such as #x^2-3x+10\lt 5x-2# . This is quadratic: the highest power of #x# that occurs is #x^2# .