SOLUTION: THe perimeter of a rectangle is 210 meters . How do i express the area as a function of the length, and how do I state the domain of the function. THis is what I have so far A

Algebra ->  Functions -> SOLUTION: THe perimeter of a rectangle is 210 meters . How do i express the area as a function of the length, and how do I state the domain of the function. THis is what I have so far A      Log On


   



Question 345735: THe perimeter of a rectangle is 210 meters . How do i express the area as a function of the length, and how do I state the domain of the function.
THis is what I have so far
A=L*W
A=X(105-X) 210/2=105
domain is 0

Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!


Set up the specific perimeter equation for this rectangle:



Solve for



Substitute this expression for into the area formula creating an expression for Area as a function of length:





Ordinarily a polynomial function would have the set of all real numbers as a domain, but this is a function that describes a physical object, and if or , then a physical rectangle no longer exists because you cannot have a 0 or negative area for a real rectangle.

Hence the domain is the interval


John

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