Question

The length of a rectangle is 5 in. more than 3 times its width. the area of the rectangle is 50in.2. a quadratic function represents the dimensions of the rectangle. what is the domain of the function?

Answer 1

The domain is actually the x value of the function, so we need to find the value of x
suppose the width is x, the length is then 3x+5
the area is 50^2 inches, so x(3x+5)=50 => 3x^2+5x-50=0
Factor this quadratic equation: (x-5)(3x+10)=0 =>x=5 or x=-10/3
width can not be negative, so the width is 5
the domain is x=5