Question

the length of a rectangle is 4 units greater than its width, and the area of the rectangle can be expressed by the equation y=x2+4x. what is a reasonable domain for this function

Answer 1

The domain of a function is the set of input or argument values for in which the function is real and defined. This is the definition of Domain. The function,y=x2+4x, has no undefined points or domain constraints. Therefore, the domain is - ∞ < x < ∞.   (∞=infinity symbol)