The length of a rectangle is 3 cm more than 10 times its width. The area of the rectangle is 75 cm2. A quadratic function can be used to represent the dimensions of the rectangle. What quantity of the rectangle represents the domain of that function? A) the area B) the width C) the length Eliminate D) the perimeter

The way the problem statement is worded, it is likely the quadratic would be written in terms of the width.

Selection B appears to be the appropriate choice.

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IMO the problem is worded in a funny way. A domain is usually a set of numbers associated with the independent variable. It appears the question is asking what is the independent variable. Given the relations stated in the problem, it could be either the width or length. It could even be the perimeter, but that is a less convenient choice for solving the rectangle. In other words, arguably any selection except A is correct. (The attachment shows quadratics in terms of width, length, and perimeter.)